sprintf

(PHP 4, PHP 5)

sprintfReturn a formatted string

Descrierea

string sprintf ( string $format [, mixed $args [, mixed $... ]] )

Returns a string produced according to the formatting string format.

Parametri

format

The format string is composed of zero or more directives: ordinary characters (excluding %) that are copied directly to the result, and conversion specifications, each of which results in fetching its own parameter. This applies to both sprintf() and printf().

Each conversion specification consists of a percent sign (%), followed by one or more of these elements, in order:

  1. An optional sign specifier that forces a sign (- or +) to be used on a number. By default, only the - sign is used on a number if it's negative. This specifier forces positive numbers to have the + sign attached as well, and was added in PHP 4.3.0.
  2. An optional padding specifier that says what character will be used for padding the results to the right string size. This may be a space character or a 0 (zero character). The default is to pad with spaces. An alternate padding character can be specified by prefixing it with a single quote ('). See the examples below.
  3. An optional alignment specifier that says if the result should be left-justified or right-justified. The default is right-justified; a - character here will make it left-justified.
  4. An optional number, a width specifier that says how many characters (minimum) this conversion should result in.
  5. An optional precision specifier in the form of a period (`.') followed by an optional decimal digit string that says how many decimal digits should be displayed for floating-point numbers. When using this specifier on a string, it acts as a cutoff point, setting a maximum character limit to the string.
  6. A type specifier that says what type the argument data should be treated as. Possible types:

    • % - a literal percent character. No argument is required.
    • b - the argument is treated as an integer, and presented as a binary number.
    • c - the argument is treated as an integer, and presented as the character with that ASCII value.
    • d - the argument is treated as an integer, and presented as a (signed) decimal number.
    • e - the argument is treated as scientific notation (e.g. 1.2e+2). The precision specifier stands for the number of digits after the decimal point since PHP 5.2.1. In earlier versions, it was taken as number of significant digits (one less).
    • E - like %e but uses uppercase letter (e.g. 1.2E+2).
    • f - the argument is treated as a float, and presented as a floating-point number (locale aware).
    • F - the argument is treated as a float, and presented as a floating-point number (non-locale aware). Available since PHP 4.3.10 and PHP 5.0.3.
    • g - shorter of %e and %f.
    • G - shorter of %E and %f.
    • o - the argument is treated as an integer, and presented as an octal number.
    • s - the argument is treated as and presented as a string.
    • u - the argument is treated as an integer, and presented as an unsigned decimal number.
    • x - the argument is treated as an integer and presented as a hexadecimal number (with lowercase letters).
    • X - the argument is treated as an integer and presented as a hexadecimal number (with uppercase letters).

Variables will be co-erced to a suitable type for the specifier:

Type Handling
Type Specifiers
string s
integer d, u, c, o, x, X, b
double g, G, e, E, f, F

Avertizare

Attempting to use a combination of the string and width specifiers with character sets that require more than one byte per character may result in unexpected results

The format string supports argument numbering/swapping. Here is an example:

Example #1 Argument swapping

<?php
$num 
5;
$location 'tree';

$format 'There are %d monkeys in the %s';
echo 
sprintf($format$num$location);
?>
This will output "There are 5 monkeys in the tree". But imagine we are creating a format string in a separate file, commonly because we would like to internationalize it and we rewrite it as:

Example #2 Argument swapping

<?php
$format 
'The %s contains %d monkeys';
echo 
sprintf($format$num$location);
?>
We now have a problem. The order of the placeholders in the format string does not match the order of the arguments in the code. We would like to leave the code as is and simply indicate in the format string which arguments the placeholders refer to. We would write the format string like this instead:

Example #3 Argument swapping

<?php
$format 
'The %2$s contains %1$d monkeys';
echo 
sprintf($format$num$location);
?>
An added benefit here is that you can repeat the placeholders without adding more arguments in the code. For example:

Example #4 Argument swapping

<?php
$format 
'The %2$s contains %1$d monkeys.
           That\'s a nice %2$s full of %1$d monkeys.'
;
echo 
sprintf($format$num$location);
?>
When using argument swapping, the n$ position specifier must come immediately after the percent sign (%), before any other specifiers, as shown in the example below.

Example #5 Position specifier with other specifiers

<?php
$format 
'The %2$s contains %1$04d monkeys';
echo 
sprintf($format$num$location);
?>

Exemplul de mai sus va afișa:

The tree contains 0005 monkeys

Notă:

Attempting to use a position specifier greater than PHP_INT_MAX will result in sprintf() generating warnings.

Avertizare

The c type specifier ignores padding and width

args

...

Valorile întoarse

Returns a string produced according to the formatting string format.

Exemple

Example #6 printf(): various examples

<?php
$n 
=  43951789;
$u = -43951789;
$c 65// ASCII 65 is 'A'

// notice the double %%, this prints a literal '%' character
printf("%%b = '%b'\n"$n); // binary representation
printf("%%c = '%c'\n"$c); // print the ascii character, same as chr() function
printf("%%d = '%d'\n"$n); // standard integer representation
printf("%%e = '%e'\n"$n); // scientific notation
printf("%%u = '%u'\n"$n); // unsigned integer representation of a positive integer
printf("%%u = '%u'\n"$u); // unsigned integer representation of a negative integer
printf("%%f = '%f'\n"$n); // floating point representation
printf("%%o = '%o'\n"$n); // octal representation
printf("%%s = '%s'\n"$n); // string representation
printf("%%x = '%x'\n"$n); // hexadecimal representation (lower-case)
printf("%%X = '%X'\n"$n); // hexadecimal representation (upper-case)

printf("%%+d = '%+d'\n"$n); // sign specifier on a positive integer
printf("%%+d = '%+d'\n"$u); // sign specifier on a negative integer
?>

Exemplul de mai sus va afișa:

%b = '10100111101010011010101101'
%c = 'A'
%d = '43951789'
%e = '4.39518e+7'
%u = '43951789'
%u = '4251015507'
%f = '43951789.000000'
%o = '247523255'
%s = '43951789'
%x = '29ea6ad'
%X = '29EA6AD'
%+d = '+43951789'
%+d = '-43951789'

Example #7 printf(): string specifiers

<?php
$s 
'monkey';
$t 'many monkeys';

printf("[%s]\n",      $s); // standard string output
printf("[%10s]\n",    $s); // right-justification with spaces
printf("[%-10s]\n",   $s); // left-justification with spaces
printf("[%010s]\n",   $s); // zero-padding works on strings too
printf("[%'#10s]\n",  $s); // use the custom padding character '#'
printf("[%10.10s]\n"$t); // left-justification but with a cutoff of 10 characters
?>

Exemplul de mai sus va afișa:

[monkey]
[    monkey]
[monkey    ]
[0000monkey]
[####monkey]
[many monke]

Example #8 sprintf(): zero-padded integers

<?php
$isodate 
sprintf("%04d-%02d-%02d"$year$month$day);
?>

Example #9 sprintf(): formatting currency

<?php
$money1 
68.75;
$money2 54.35;
$money $money1 $money2;
// echo $money will output "123.1";
$formatted sprintf("%01.2f"$money);
// echo $formatted will output "123.10"
?>

Example #10 sprintf(): scientific notation

<?php
$number 
362525200;

echo 
sprintf("%.3e"$number); // outputs 3.625e+8
?>

Vedeți de asemenea

  • printf() - Output a formatted string
  • sscanf() - Parses input from a string according to a format
  • fscanf() - Parses input from a file according to a format
  • vsprintf() - Return a formatted string
  • number_format() - Format a number with grouped thousands

add a note add a note

User Contributed Notes 52 notes

up
19
Jay Gilford
5 years ago
I created this function a while back to save on having to combine mysql_real_escape_string onto all the params passed into a sprintf. it works literally the same as the sprintf other than that it doesn't require you to escape your inputs. Hope its of some use to people

<?php
function mressf()
{
   
$args = func_get_args();
    if (
count($args) < 2)
        return
false;
   
$query = array_shift($args);
   
$args = array_map('mysql_real_escape_string', $args);
   
array_unshift($args, $query);
   
$query = call_user_func_array('sprintf', $args);
    return
$query;
}
?>

Regards
Jay
Jaygilford.com
up
3
david at rayninfo dot co dot uk
9 years ago
Using sprintf to force leading leading zeros

foreach (range(1, 10) as $v) {echo "<br>tag_".sprintf("%02d",$v);}

displays
tag_01
tag_02
tag_03
.. etc
up
14
Alex R. Gibbs
1 year ago
1.  A plus sign ('+') means put a '+' before positive numbers while a minus sign ('-') means left justify.  The documentation incorrectly states that they are interchangeable.  They produce unique results that can be combined:

<?php
echo sprintf ("|%+4d|%+4d|\n",   1, -1);
echo
sprintf ("|%-4d|%-4d|\n",   1, -1);
echo
sprintf ("|%+-4d|%+-4d|\n", 1, -1);
?>

outputs:

|  +1|  -1|
|1   |-1  |
|+1  |-1  |

2.  Padding with a '0' is different than padding with other characters.  Zeros will only be added at the front of a number, after any sign.  Other characters will be added before the sign, or after the number:

<?php
echo sprintf ("|%04d|\n",   -2);
echo
sprintf ("|%':4d|\n",  -2);
echo
sprintf ("|%-':4d|\n", -2);

// Specifying both "-" and "0" creates a conflict with unexpected results:
echo sprintf ("|%-04d|\n",  -2);

// Padding with other digits behaves like other non-zero characters:
echo sprintf ("|%-'14d|\n", -2);
echo
sprintf ("|%-'04d|\n", -2);
?>

outputs:

|-002|
|::-2|
|-2::|
|-2  |
|-211|
|-2  |
up
6
jfgrissom at gmail dot com
5 years ago
I had a nightmare trying to find the two's complement of a 32 bit number.

I got this from http://www.webmasterworld.com/forum88/13334.htm (credit where credit is due... =P  )

Quote: ...find out the 2's complement of any number, which is -(pow(2, n) - N) where n is the number of bits and N is the number for which to find out its 2's complement.

This worked magic for me... previously I was trying to use

sprintf ("%b",$32BitDecimal);
But it always returned 10000000000000000000000 when the $32BitDecimal value got above 2,000,000,000.

This -(pow(2, n) - N)
Worked remarkably well and was very accurate.

Hope this helps someone fighting with two's complement in PHP.
up
11
matt
6 years ago
Was looking for a assoc way of using sprintf but couldnt find one, probably wasnt looking hard enough so came up with this. Very very simple indeed...

<?php

function sprintf2($str='', $vars=array(), $char='%')
{
    if (!
$str) return '';
    if (
count($vars) > 0)
    {
        foreach (
$vars as $k => $v)
        {
           
$str = str_replace($char . $k, $v, $str);
        }
    }

    return
$str;
}

echo
sprintf2('Hello %your_name my name is %my_name! I am %my_age, how old are you? I like %object!', array(
   
'your_name' => 'Ben',
   
'my_name' => 'Matt',
   
'my_age' => '21',
   
'object' => 'food'
));

// Hello Ben my name is Matt! I am 21, how old are you? I like food!

?>

Looks nice anyway :)
up
4
bknakkerNO at SPAMgmail dot com
8 years ago
Note that in PHP5 (.1.4 for me) sprintf will not use the __toString function of an object.

<?php
class pr{
private
$l;
public function
__construct($l)
{
$this->l=$l;
}
public function
__toString()
{
return
$this->l;
}
}
echo new
pr('This works!!'); //This will display 'This works!!'
echo sprintf(new pr('This doesnt')); // will display 'Object'
?>

Be careful with that!
up
4
Pacogliss
9 years ago
Just a reminder for beginners : example 6 'printf("[%10s]\n",    $s);' only works (that is, shows out the spaces) if you put the html '<pre></pre>' tags ( head-scraping time saver ;-).
up
3
php at sharpdreams dot com
10 years ago
Note that when using the argument swapping, you MUST number every argument, otherwise sprintf gets confused. This only happens if you use number arguments first, then switch to a non-numbered, and then back to a numbered one.

<?php
$sql
= sprintf( "select * from %1\$s left join %2\$s on( %1\$s.id = %2\$s.midpoint ) where %1\$s.name like '%%%s%%' and %2\$s.tagname is not null", "table1", "table2", "bob" );
// Wont work:
// Sprintf will complain about not enough arguments.
$sql = sprintf( "select * from %1\$s left join %2\$s on( %1\$s.id = %2\$s.midpoint ) where %1\$s.name like '%%%3\$s%%' and %2\$s.tagname is not null", "table1", "table2", "bob" );
// Will work: note the %3\$s
?>
up
5
Hayley Watson
2 years ago
If you use argument numbering, then format specifications with the same number get the same argument; this can save repeating the argument in the function call.

<?php

$pattern
= '%1$s %1$\'#10s %1$s!';

printf($pattern, "badgers");
?>
up
5
christian at wenz dot org
9 years ago
@ henke dot andersson at comhem dot se: Use vprintf()/vsprintf() for that.
up
1
geertdd at gmail dot com
4 years ago
Note that when using a sign specifier, the number zero is considered positive and a "+" sign will be prepended to it.

<?php
printf
('%+d', 0); // +0
?>
up
1
viktor at textalk dot com
5 years ago
A more complete and working version of mb_sprintf and mb_vsprintf. It should work with any "ASCII preserving" encoding such as UTF-8 and all the ISO-8859 charsets. It handles sign, padding, alignment, width and precision. Argument swapping is not handled.

<?php
if (!function_exists('mb_sprintf')) {
  function
mb_sprintf($format) {
     
$argv = func_get_args() ;
     
array_shift($argv) ;
      return
mb_vsprintf($format, $argv) ;
  }
}
if (!
function_exists('mb_vsprintf')) {
 
/**
   * Works with all encodings in format and arguments.
   * Supported: Sign, padding, alignment, width and precision.
   * Not supported: Argument swapping.
   */
 
function mb_vsprintf($format, $argv, $encoding=null) {
      if (
is_null($encoding))
         
$encoding = mb_internal_encoding();

     
// Use UTF-8 in the format so we can use the u flag in preg_split
     
$format = mb_convert_encoding($format, 'UTF-8', $encoding);

     
$newformat = ""; // build a new format in UTF-8
     
$newargv = array(); // unhandled args in unchanged encoding

     
while ($format !== "") {
     
       
// Split the format in two parts: $pre and $post by the first %-directive
        // We get also the matched groups
       
list ($pre, $sign, $filler, $align, $size, $precision, $type, $post) =
           
preg_split("!\%(\+?)('.|[0 ]|)(-?)([1-9][0-9]*|)(\.[1-9][0-9]*|)([%a-zA-Z])!u",
                      
$format, 2, PREG_SPLIT_DELIM_CAPTURE) ;

       
$newformat .= mb_convert_encoding($pre, $encoding, 'UTF-8');
       
        if (
$type == '') {
         
// didn't match. do nothing. this is the last iteration.
       
}
        elseif (
$type == '%') {
         
// an escaped %
         
$newformat .= '%%';
        }
        elseif (
$type == 's') {
         
$arg = array_shift($argv);
         
$arg = mb_convert_encoding($arg, 'UTF-8', $encoding);
         
$padding_pre = '';
         
$padding_post = '';
         
         
// truncate $arg
         
if ($precision !== '') {
           
$precision = intval(substr($precision,1));
            if (
$precision > 0 && mb_strlen($arg,$encoding) > $precision)
             
$arg = mb_substr($precision,0,$precision,$encoding);
          }
         
         
// define padding
         
if ($size > 0) {
           
$arglen = mb_strlen($arg, $encoding);
            if (
$arglen < $size) {
              if(
$filler==='')
                 
$filler = ' ';
              if (
$align == '-')
                 
$padding_post = str_repeat($filler, $size - $arglen);
              else
                 
$padding_pre = str_repeat($filler, $size - $arglen);
            }
          }
         
         
// escape % and pass it forward
         
$newformat .= $padding_pre . str_replace('%', '%%', $arg) . $padding_post;
        }
        else {
         
// another type, pass forward
         
$newformat .= "%$sign$filler$align$size$precision$type";
         
$newargv[] = array_shift($argv);
        }
       
$format = strval($post);
      }
     
// Convert new format back from UTF-8 to the original encoding
     
$newformat = mb_convert_encoding($newformat, $encoding, 'UTF-8');
      return
vsprintf($newformat, $newargv);
  }
}
?>
up
2
jaimthorn at yahoo dot com
6 years ago
I needed a piece of code similar to the one Matt posted below, on the 10th of March, 2008.  However, I wasn't completely satisfied with Matt's code (sorry, Matt!  No offense intended!), because

1) I don't like to initialize variables when it's not really needed, and
2) it contains two bugs.

What are the bugs?

First, Matt's code tests for count($vars) > 0, but if $var == "Hello world!", then count($var) == 1, but the foreach() will crash because $var has to be an array.  So instead, my code tests for is_array($var).

Second, if a key in $vars is a prefix of any of the later keys in the array (like 'object' is the beginning of 'objective') then the str_replace messes things up.  This is no big deal if your keys are hard-coded and you can make sure the keys don't interfere, but in my code the keys are variable.  So I decided to first sort the array on a decreasing length of the key.

<?php

function cmp($a, $b)
{
    return
strlen($b) - strlen($a);
}

function
sprintf2($str, $vars, $char = '%')
{
    if(
is_array($vars))
    {
       
uksort($vars, "cmp");

        foreach(
$vars as $k => $v)
        {
           
$str = str_replace($char . $k, $v, $str);
        }
    }

    return
$str;
}

echo
sprintf2( 'Hello %your_name, my name is %my_name! I am %my_age, how old are you? I like %object and I want to %objective_in_life!'
            
, array( 'your_name'         => 'Matt'
                   
, 'my_name'           => 'Jim'
                   
, 'my_age'            => 'old'
                   
, 'object'            => 'women'
                   
, 'objective_in_life' => 'write code'
                   
)
             );

?>

If possible, and if you're willing, you can also embed the key fields in the text between percent-signs, rather than prefixing the keys with one.  Sorting is no longer necessary, and the execution time is less than half of the code above:

<?php

function sprintf3($str, $vars, $char = '%')
{
   
$tmp = array();
    foreach(
$vars as $k => $v)
    {
       
$tmp[$char . $k . $char] = $v;
    }
    return
str_replace(array_keys($tmp), array_values($tmp), $str);
}

echo
sprintf3( 'Hello %your_name%, my name is %my_name%! I am %my_age%, how old are you? I like %object% and I want to %objective_in_life%!'
            
, array( 'your_name'         => 'Matt'
                   
, 'my_name'           => 'Jim'
                   
, 'my_age'            => 'old'
                   
, 'object'            => 'women'
                   
, 'objective_in_life' => 'write code'
                   
)
             );
?>

If you're willing to embed the keys in the text, you may also be willing to embed the keys themselves in percent signs, thus shaving off another 30% of the execution time:

<?php

function sprintf4($str, $vars)
{
    return
str_replace(array_keys($vars), array_values($vars), $str);
}

echo
sprintf4( 'Hello %your_name%, my name is %my_name%! I am %my_age%, how old are you? I like %object% and I want to %objective_in_life%!'
            
, array( '%your_name%'         => 'Matt'
                   
, '%my_name%'           => 'Jim'
                   
, '%my_age%'            => 'old'
                   
, '%object%'            => 'women'
                   
, '%objective_in_life%' => 'write code'
                   
)
             );
?>

Of course, by now the sprintf function is no longer something you'd want to write to mum and dad about...
up
2
John Walker
5 years ago
To add to other notes below about floating point problems, I noted that %f and %F will apparently output a maximum precision of 6 as a default so you have to specify 1.15f (eg) if you need more.

In my case, the input (from MySQL) was a string with 15 digits of precision that was displayed with 6. Likely what happens is that the rounding occurs in the conversion to a float before it is displayed. Displaying it as 1.15f (or in my case, %s) shows the correct number.
up
1
scott dot gardner at mac dot com
6 years ago
In the last example of Example#6, there is an error regarding the output.

printf("[%10.10s]\n", $t); // left-justification but with a cutoff of 10 characters

This outputs right-justified.

In order to output left-justified:

printf("[%-10.10s]\n", $t);
up
1
webmaster at cafe-clope dot net
9 years ago
trying to fix the multibyte non-compliance of sprintf, I came to that :

<?php
function mb_sprintf($format) {
   
$argv = func_get_args() ;
   
array_shift($argv) ;
    return
mb_vsprintf($format, $argv) ;
}

function
mb_vsprintf($format, $argv) {
   
$newargv = array() ;
   
   
preg_match_all("`\%('.+|[0 ]|)([1-9][0-9]*|)s`U", $format, $results, PREG_SET_ORDER) ;
   
    foreach(
$results as $result) {
        list(
$string_format, $filler, $size) = $result ;
        if(
strlen($filler)>1)
           
$filler = substr($filler, 1) ;
        while(!
is_string($arg = array_shift($argv)))
           
$newargv[] = $arg ;
       
$pos = strpos($format, $string_format) ;
       
$format = substr($format, 0, $pos)
                  . (
$size ? str_repeat($filler, $size-strlen($arg)) : '')
                    .
str_replace('%', '%%', $arg)
                    .
substr($format, $pos+strlen($string_format))
                    ;
    }
       
    return
vsprintf($format, $newargv) ;
}

?>

handle with care :
1. that function was designed mostly for utf-8. i guess it won't work with any static mb encoding.
2. my configuration sets the mbstring.func_overload configuration directive to 7, so you may wish to replace substr, strlen, etc. with mb_* equivalents.
3. since preg_* doesn't complies with mb strings, I used a '.+' in the regexp to symbolize an escaped filler character. That means, %'xy5s pattern will match, unfortunately. It is recomended to remove the '+', unless you are intending to use an mb char as filler.
4. the filler fills at left, and only at left.
5. I couldn't succeed with a preg_replace thing : the problem was to use the differents lengths of the string arguements in the same replacement, string or callback. That's why the code is much longuer than I expected.
6. The pattern wil not match any %1\$s thing... just was too complicated for me.
7. Although it has been tested, and works fine within the limits above, this is much more a draft than a end-user function. I would enjoy any improvment.

The test code below shows possibilities, and explains the problem that occures with an mb string argument in sprintf.

<?php
header
("content-type:text/plain; charset=UTF-8") ;
$mb_string = "xxx" ;
echo
sprintf("%010s", $mb_string), " [octet-size: ", str_sizeof($mb_string) , " ; count: ", strlen(sprintf("%010s", $mb_string)), " characters]\n" ;
echo
mb_sprintf("%010s", $mb_string), " [octet-size: ", str_sizeof($mb_string) , " ; count: ", strlen(mb_sprintf("%010s", $mb_string)), " characters]\n" ;
echo
"\n" ;
echo
mb_sprintf("%''10s\n%'010s\n%'10s\n%10d\n%'x10s\n%010s\n% 10s\n%010s\n%'1s\n", "zero", "one", "two", 3, "four", "ve", "%s%i%x", "ve", "eight") ;
?>
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1
dwieeb at gmail dot com
4 years ago
If you use the default padding specifier (a space) and then print it to HTML, you will notice that HTML does not display the multiple spaces correctly. This is because any sequence of white-space is treated as a single space.

To overcome this, I wrote a simple function that replaces all the spaces in the string returned by sprintf() with the character entity reference "&nbsp;" to achieve non-breaking space in strings returned by sprintf()

<?php
//Here is the function:
function sprintf_nbsp() {
  
$args = func_get_args();
   return
str_replace(' ', '&nbsp;', vsprintf(array_shift($args), array_values($args)));
}

//Usage (exactly like sprintf):
$format = 'The %d monkeys are attacking the [%10s]!';
$str = sprintf_nbsp($format, 15, 'zoo');
echo
$str;
?>

The above example will output:
The 15 monkeys are attacking the [       zoo]!

<?php
//The variation that prints the string instead of returning it:
function printf_nbsp() {
  
$args = func_get_args();
   echo
str_replace(' ', '&nbsp;', vsprintf(array_shift($args), array_values($args)));
}
?>
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1
henke dot andersson at comhem dot se
9 years ago
Mind that it doesn't allow you to use a array as multiple arguments like this:
<?php
printf
('%s %s',array('a','b')) ?>
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1
nate at frickenate dot com
5 years ago
Here's a clean, working version of functions to allow using named arguments instead of numeric ones. ex: instead of sprintf('%1$s', 'Joe');, we can use sprintf('%name$s', array('name' => 'Joe'));. I've provided 2 different versions: the first uses the php-like syntax (ex: %name$s), while the second uses the python syntax (ex: %(name)s).

<?php

/**
* version of sprintf for cases where named arguments are desired (php syntax)
*
* with sprintf: sprintf('second: %2$s ; first: %1$s', '1st', '2nd');
*
* with sprintfn: sprintfn('second: %second$s ; first: %first$s', array(
*  'first' => '1st',
*  'second'=> '2nd'
* ));
*
* @param string $format sprintf format string, with any number of named arguments
* @param array $args array of [ 'arg_name' => 'arg value', ... ] replacements to be made
* @return string|false result of sprintf call, or bool false on error
*/
function sprintfn ($format, array $args = array()) {
   
// map of argument names to their corresponding sprintf numeric argument value
   
$arg_nums = array_slice(array_flip(array_keys(array(0 => 0) + $args)), 1);

   
// find the next named argument. each search starts at the end of the previous replacement.
   
for ($pos = 0; preg_match('/(?<=%)([a-zA-Z_]\w*)(?=\$)/', $format, $match, PREG_OFFSET_CAPTURE, $pos);) {
       
$arg_pos = $match[0][1];
       
$arg_len = strlen($match[0][0]);
       
$arg_key = $match[1][0];

       
// programmer did not supply a value for the named argument found in the format string
       
if (! array_key_exists($arg_key, $arg_nums)) {
           
user_error("sprintfn(): Missing argument '${arg_key}'", E_USER_WARNING);
            return
false;
        }

       
// replace the named argument with the corresponding numeric one
       
$format = substr_replace($format, $replace = $arg_nums[$arg_key], $arg_pos, $arg_len);
       
$pos = $arg_pos + strlen($replace); // skip to end of replacement for next iteration
   
}

    return
vsprintf($format, array_values($args));
}

/**
* version of sprintf for cases where named arguments are desired (python syntax)
*
* with sprintf: sprintf('second: %2$s ; first: %1$s', '1st', '2nd');
*
* with sprintfn: sprintfn('second: %(second)s ; first: %(first)s', array(
*  'first' => '1st',
*  'second'=> '2nd'
* ));
*
* @param string $format sprintf format string, with any number of named arguments
* @param array $args array of [ 'arg_name' => 'arg value', ... ] replacements to be made
* @return string|false result of sprintf call, or bool false on error
*/
function sprintfn ($format, array $args = array()) {
   
// map of argument names to their corresponding sprintf numeric argument value
   
$arg_nums = array_slice(array_flip(array_keys(array(0 => 0) + $args)), 1);

   
// find the next named argument. each search starts at the end of the previous replacement.
   
for ($pos = 0; preg_match('/(?<=%)\(([a-zA-Z_]\w*)\)/', $format, $match, PREG_OFFSET_CAPTURE, $pos);) {
       
$arg_pos = $match[0][1];
       
$arg_len = strlen($match[0][0]);
       
$arg_key = $match[1][0];

       
// programmer did not supply a value for the named argument found in the format string
       
if (! array_key_exists($arg_key, $arg_nums)) {
           
user_error("sprintfn(): Missing argument '${arg_key}'", E_USER_WARNING);
            return
false;
        }

       
// replace the named argument with the corresponding numeric one
       
$format = substr_replace($format, $replace = $arg_nums[$arg_key] . '$', $arg_pos, $arg_len);
       
$pos = $arg_pos + strlen($replace); // skip to end of replacement for next iteration
   
}

    return
vsprintf($format, array_values($args));
}

?>
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1
john at jbwalker dot com
6 months ago
I couldn't find what should be a WARNING in the documentation above, that if you have more specifiers than variables to match them sprintf returns NOTHING. This fact, IMHO, should also be noted under return values.
up
1
me at php dot net
1 year ago
To convert / use / implement 64-bit signed 2's complement Long type values in PHP code, use the following code

// requires bcmath

/* java 64-bit long: The long data type is a 64-bit signed two's complement integer. It has a minimum value of -9,223,372,036,854,775,808 and a maximum value of 9,223,372,036,854,775,807 (inclusive). Use this data type when you need a range of values wider than those provided by int.
*/

bcscale(0);

$num = substr($data,0,8) // 8 binary bytes from file

$long  = bcadd(bcmul(unpack('N',substr($num,0,4))[1],bcpow(2,32)),unpack('N',substr($num,4,4))[1]);

if(unpack('N',substr($num,4,4))[1] & 0x80000000)
  $long = bcadd($long,pow(2,32));

var_dump($long);

// now you can use $long as 64-bit signed long value by using bcmath functions
// do not use php math funcs, they cant handle 64-bit long integer values
// use bcadd bcsub etc from bcmath functions freely

Hope this helps people handling 64-bit long values retrieved from other languages like java, etc
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1
timo dot frenay at gmail dot com
3 years ago
Here is how to print a floating point number with 16 significant digits regardless of magnitude:

<?php
    $result
= sprintf(sprintf('%%.%dF', max(15 - floor(log10($value)), 0)), $value);
?>

This works more reliably than doing something like sprintf('%.15F', $value) as the latter may cut off significant digits for very small numbers, or prints bogus digits (meaning extra digits beyond what can reliably be represented in a floating point number) for very large numbers.
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1
remy dot damour at -please-no-spam-laposte dot net
5 years ago
With printf() and sprintf() functions, escape character is not backslash '\' but rather '%'.

Ie. to print '%' character you need to escape it with itself:
<?php
printf
('%%%s%%', 'koko'); #output: '%koko%'
?>
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1
php at mikeboers dot com
6 years ago
And continuing on the same theme of a key-based sprintf...

I'm roughly (I can see a couple cases where it comes out wierd) copying the syntax of Python's string formatting with a dictionary. The improvement over the several past attempts is that this one still respects all of the formating options, as you can see in my example.

And the error handling is really crappy (just an echo). I just threw this together so do with it what you will. =]

<?php

function sprintf_array($string, $array)
{
   
$keys    = array_keys($array);
   
$keysmap = array_flip($keys);
   
$values  = array_values($array);
   
    while (
preg_match('/%\(([a-zA-Z0-9_ -]+)\)/', $string, $m))
    {   
        if (!isset(
$keysmap[$m[1]]))
        {
            echo
"No key $m[1]\n";
            return
false;
        }
       
       
$string = str_replace($m[0], '%' . ($keysmap[$m[1]] + 1) . '$', $string);
    }
   
   
array_unshift($values, $string);
   
var_dump($values);
    return
call_user_func_array('sprintf', $values);
}

echo
sprintf_array('4 digit padded number: %(num)04d ', array('num' => 42));

?>

Cheers!
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1
ranema at ubuntu dot polarhome dot com
6 years ago
It's very comfortible for long Sql queries:

<?php
$_gQuery
= "UPDATE `x` SET `a` = %i AND `b` = '%s' WHERE `my` = '%s';"; // ........

mysql_query( sprintf( $_gQuery, 10, 'a', 'rrrr' ) );
?>

But if you have a short query, then it would be much faster to append your data by using `.`.

<?php
$_gQuery
= 'SELECT COUNT(*) FROM `' . $_gName . '`;';
?>
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1
me at umarfarooq dot net
7 years ago
/**
This function returns a formated  string with the legnth you specify
@string holds the string which you want to format
@len holds the length you want to format
**/
function formatString($string, $len)
{
    if (strlen($string) < $len)
    {
        $addchar=($len - strlen($string)) ;
        for ($i = 0; $i < $addchar; $i++)
        {
            $string=sprintf("$string%s", "0");
        }
    }
   
    if (strlen($string) > $len)
    {
        $string=substr($string,0,$len);
    }
   
    return $string;   
}
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1
Thomas Breuss
7 years ago
Note:
If you want to use % in sprintf, you have to "quote" it like %%.

Example:
echo sprintf("Green => %d%%'", 50);

Output:
Green => 50%
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1
tim dot brouckaert dot NOSPAM at gmail dot com
9 years ago
If you want to center align some text using the printf or sprintf functions, you can just use the following:

function center_text($word){
    $tot_width = 30;
    $symbol = "-";
    $middle = round($tot_width/2);
    $length_word = strlen($word);
    $middle_word = round($length_word / 2);
    $last_position = $middle + $middle_word;
    $number_of_spaces = $middle - $middle_word;

    $result = sprintf("%'{$symbol}{$last_position}s", $word);
        for ($i = 0; $i < $number_of_spaces; $i++){
            $result .= "$symbol";
        }
    return $result;
}

$string = "This is some text";
print center_text($string);

off course you can modify the function to use more arguments.
up
0
hdimac at gmail dot com
7 months ago
In the examples, is being shown printf, but it should say sprintf, which is the function being explained... just a simple edition mistake.
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0
ivan at php dot net
11 months ago
There is a minor issue in a code of mb_vsprintf function from viktor at textalk dot com.

In "truncate $arg" section the following line:
  $arg = mb_substr($precision,0,$precision,$encoding);
needs to be replaced with:
  $arg = mb_substr($arg,0,$precision,$encoding);
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1
Gkeeper80
10 years ago
When using sprintf with padding, it's important to note that specifying the length of your padding does not restrict the length of your output.

For example:
$var = 'test';
$output sprintf("%03s", $var);

print $output;

Produces:
test

NOT:
est

This may seem intuitive for working with numbers, but not neccesarily when working with strings.
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1
info at nospam dot webtip dot dk
11 years ago
If you want to format a phonenumber with spaces, use chunk_split() which splits a string into smaller chunks. It's much simpler than using sprintf.

$phone = "12345678";

chunk_split ($phone, 2);

will return 12 34 56 78
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1
no dot email dot address at example dot com
12 years ago
Using argument swapping in sprintf() with gettext: Let's say you've written the following script:

<?php
$var
= sprintf(gettext("The %2\$s contains %1\$d monkeys"), 2, "cage");
?>

Now you run xgettext in order to generate a .po file. The .po file will then look like this:

#: file.php:9
#, ycp-format
msgid "The %2\\$s contains %1\\$d monkeys"
msgstr ""

Notice how an extra backslash has been added by xgettext.

Once you've translated the string, you must remove all backslashes from the ID string as well as the translation, so the po file will look like this:

#: file.php:9
#, ycp-format
msgid "The %2$s contains %1$d monkeys"
msgstr "Der er %1$d aber i %2$s"

Now run msgfmt to generate the .mo file, restart Apache to remove the gettext cache if necessary, and you're off.
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0
krzysiek dot 333 at gmail dot com - zryty dot hekko dot pl
3 years ago
Encoding and decoding IP adress to format: 1A2B3C4D (mysql column: char(8) )

<?php
function encode_ip($dotquad_ip)
{
   
$ip_sep = explode('.', $dotquad_ip);
    return
sprintf('%02x%02x%02x%02x', $ip_sep[0], $ip_sep[1], $ip_sep[2], $ip_sep[3]);
}

function
decode_ip($int_ip)
{
   
$hexipbang = explode('.', chunk_split($int_ip, 2, '.'));
    return
hexdec($hexipbang[0]). '.' . hexdec($hexipbang[1]) . '.' . hexdec($hexipbang[2]) . '.' . hexdec($hexipbang[3]);
}
?>
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1
cv at corbach dot de
12 years ago
To make radu.rendec@ines.ro's excellent function work on signed numbers you must change the first line to:

$e = floor(log10(abs($x)));
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0
carmageddon at gmail dot com
3 years ago
If you want to convert a decimal (integer) number into constant length binary number in lets say 9 bits, use this:

$binary = sprintf('%08b', $number );

for example:
<?php
$bin
= sprintf('%08b',511 );
echo
$bin."\n";
?>

would output 111111111
And 2 would output 00000010

I know the leading zeros are useful to me, perhaps they are to someone else too.
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1
tjchamberlain.hotmail@com
13 years ago
It is worth noting that "%5.2f" will result in a string 8 characters long (5 then the '.' then 2), not 5 characters as you might expect.
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1
voudras at nospam dot swiftslayer dot org
14 years ago
Little note about sprintf and its ilk.
if you attempt something like
$string = "dingy%sflem%dwombat";
$nbr = 5;
$name = "voudras";

$msg = sprintf("%d $string %s", $nbr, $name);

sprintf will complain about a lack in the number of arguments, this would be because of the %'s in the actual string. This can be a great benifit, but is also rather confusing if you dont realize this feature, and are passing questionable variables to sprintf (for, say perhaps logging). One way around this is using
ereg_replace("%","%%", $string); before
sending it off to sprintf. This is actually how i came across this as a problem - i had realized some time ago that i would have to test my $string for
%'s, but when running the %->%% replacement on a very large serialized object, my application timed out.
    My solution was to use
sprintf("%d %s %s", $nbr, $string, $name);
but, there was a reason i originally had done this the other way - i suppose i'll find out soon enough
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0
Astone
5 years ago
When you're using Google translator, you have to 'escape' the 'conversion specifications' by putting <span class="notranslate"></span> around them.

Like this:

<?php

function getGoogleTranslation($sString, $bEscapeParams = true)
{
   
// "escape" sprintf paramerters
   
if ($bEscapeParams)
    {
       
$sPatern = '/(?:%%|%(?:[0-9]+\$)?[+-]?(?:[ 0]|\'.)?-?[0-9]*(?:\.[0-9]+)?[bcdeufFosxX])/';       
       
$sEscapeString = '<span class="notranslate">$0</span>';
       
$sString = preg_replace($sPatern, $sEscapeString, $sString);
    }

   
// Compose data array (English to Dutch)
   
$aData = array(
       
'v'            => '1.0',
       
'q'            => $sString,
       
'langpair'    => 'en|nl',
    );

   
// Initialize connection
   
$rService = curl_init();
   
   
// Connection settings
   
curl_setopt($rService, CURLOPT_URL, 'http://ajax.googleapis.com/ajax/services/language/translate');
   
curl_setopt($rService, CURLOPT_RETURNTRANSFER, true);
   
curl_setopt($rService, CURLOPT_POSTFIELDS, $aData);
   
   
// Execute request
   
$sResponse = curl_exec($rService);

   
// Close connection
   
curl_close($rService);
   
   
// Extract text from JSON response
   
$oResponse = json_decode($sResponse);
    if (isset(
$oResponse->responseData->translatedText))
    {
       
$sTranslation = $oResponse->responseData->translatedText;
    }
    else
    {
       
// If some error occured, use the original string
       
$sTranslation = $sString;
    }
   
   
// Replace "notranslate" tags
   
if ($bEscapeParams)
    {
       
$sEscapePatern = '/<span class="notranslate">([^<]*)<\/span>/';
       
$sTranslation = preg_replace($sEscapePatern, '$1', $sTranslation);
    }
   
   
// Return result
   
return $sTranslation;
}

?>

Thanks to MelTraX for defining the RegExp!
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0
splogamurugan at gmail dot com
5 years ago
$format = 'There are %1$d monkeys in the %s and %s ';
printf($format, 100, 'Chennai', 'Bangalore');

Expecting to output
"There are 100 monkeys in the Chennai and bangalore"

But, this will output
"There are 100 monkeys in the 100 and Chennai"

Because, the second and Third specifiers takes 1rst and 2nd arguments. Because it is not assigned with any arguments.
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0
MelTraX
6 years ago
<?php
 
// parses a string meant for printf and returns an array of found parameters (or NULL if it contains syntax errors)
 
function parsePrintfParameters($string) {
   
$valid = '/^(?:%%|%(?:[0-9]+\$)?[+-]?(?:[ 0]|\'.)?-?[0-9]*(?:\.[0-9]+)?[bcdeufFosxX])/';
   
$originalString = $string;

   
$result = array();
    while(
strlen($string)) {
      if(!
$string = preg_replace('/^[^%]*/', '', $string))
        break;

      if(
preg_match($valid, $string, $matches)) {
       
$result[] = $matches[0];
       
$string = substr($string, strlen($matches[0]));
      } else {
       
error(sprintf('"%s" has an error near "%s".', $originalString, $string));
        return
NULL;
      }
    }
    return
$result;
  }
?>
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0
ant at loadtrax dot com
6 years ago
Rounding seems a little inconsistent, so beware:

$ php -a

php> print round(1.0*20*1.175/100,2);
0.24
php > print sprintf("%.2f",1.0*20*1.175/100);
0.23
php > print sprintf("%.0f",1.0*20*1.175);
24

I get round this by doing the round first, then doing the sprintf.
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0
SWestrup
8 years ago
In response to Anonymous, who claimed that:

  printf("[%s]\n", str_pad('Hello', 20));

and

  printf("[%-20s]\n", 'Hello');

are the same thing: you've missed the point.

They're only the same when the amount of padding is a known constant. When its a variable (or an expression), its often much more convenient to be able to write:

  printf("[%-*s]\n", 3*$n+2, "Hello");

than what you have to go through now, which is either:

  $t = 3*$n+2;
  printf("[%-{$t}s]\n","Hello");

or

  printf("[%s]\n", str_pad('Hello', 3*$n+2));
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0
ian dot w dot davis at gmail dot com
9 years ago
Just to elaborate on downright's point about different meanings for %f, it appears the behavior changed significantly as of 4.3.7, rather than just being different on different platforms. Previously, the width specifier gave the number of characters allowed BEFORE the decimal. Now, the width specifier gives the TOTAL number of characters. (This is in line with the semantics of printf() in other languages.) See bugs #28633 and #29286 for more details.
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0
jrpozo at conclase dot net
9 years ago
Be careful if you use the %f modifier to round decimal numbers as it (starting from 4.3.10) will no longer produce a float number if you set certain locales, so you can't accumulate the result. For example:

setlocale(LC_ALL, 'es_ES');
echo(sprintf("%.2f", 13.332) + sprintf("%.2f", 14.446))

gives 27 instead of 27.78, so use %F instead.
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0
timo at frenay dot net
9 years ago
Note that the documentation is unclear about the details of the sign specifier. First of all, the character for this is "+".

Also note that the following does NOT print "+00.00" as you might expect:

<?php
    printf
('%+02.2f', 0);
?>

The sign is included in the width. This can't be solved by increasing the width:

<?php
    printf
('%+03.2f', 0);
?>

This will put the padding 0 before the sign.
Here is a possible solution:

<?php
    $value
= 0;
   
printf('%s%02.2f', ($value < 0) ? '-' : '+', abs($value));
?>
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0
kekec at kukac dot hu
10 years ago
A really working one:
<?php
function cutzero($value) {
   return
preg_replace("/(\.?)0+$/", "", $value);
}
?>
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0
abiltcliffe at bigfoot.com
12 years ago
To jrust at rustyparts.com, note that if you're using a double-quoted string and *don't* escape the dollar sign with a backslash, $s and $d will be interpreted as variable references. The backslash isn't part of the format specifier itself but you do need to include it when you write the format string (unless you use single quotes).
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0
Andrew dot Wright at spamsux dot atnf dot csiro dot au
12 years ago
An error in my last example:
$b = sprintf("%30.s", $a);
will only add enough spaces before $a to pad the spaces + strlen($a) to 30 places.

My method of centering fixed text in a 72 character width space is:

$a = "Some string here";
$lwidth = 36; // 72/2
$b = sprintf("%".($lwidth + round(strlen($a)/2)).".s", $a);
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0
prolixmp3 at navigators dot lv
13 years ago
If you are going to create a counter which uses _symbols_ before actual digits (see, f.e., SpyLog.com counters - they are filling space with "." before, so the count like 12345 looks like "........12345"), you can use the following:

$txt = "Abracadabra"; // actual string
$fit = 16; // how many digits to use
$fill = "."; // what to fill
$digits = sprintf ("%'{$fill}{$fit}s", $txt);

Paul (a.k.a. Mr.Prolix)
up
-1
ignat dot scheglovskiy at gmail dot com
2 years ago
Here is an example how alignment, padding and precision specifier can be used to print formatted list of items:

<?php

$out
= "The Books\n";
$books = array("Book 1", "Book 2", "Book 3");
$pages = array("123 pages ", "234 pages", "345 pages");
for (
$i = 0; $i < count($books); $i++) {
   
$out .= sprintf("%'.-20s%'.7.4s\n", $books[$i], $pages[$i]);
}
echo
$out;

// Outputs:
//
// The Books
// Book 1.................123
// Book 2.................234
// Book 3.................345
?>
up
-1
ethaizone at hotmail dot com
1 year ago
Example:  use sprintf to zero fill

<?php
// 00000005
echo sprintf('%08d', 5);
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