chr

(PHP 4, PHP 5, PHP 7, PHP 8)

chr — Générer une chaîne d'un octet à partir d'un nombre

Description

chr(int $codepoint): string

Retourne une chaîne de caractères d'un seul caractère contenant le caractère spécifié en interprétant codepoint comme un entier non signé.

Ceci peut être utilisé pour créer une chaîne de caractères d'un seul caractère dans un encodage sur un octet tel que ASCII, ISO-8859, ou Windows 1252, en passant la position du caractère désiré dans la table de correspondance de l'encodage. Cependant, il est à noter que cette fonction n'est pas conscient d'aucun encodage de chaîne de caractères, et en particulier ne peut pas être transmit une valeur de point de code Unicode pour générer une chaîne de caractères dans un encodage multioctet tel que UTF-8 ou UTF-16.

Cette fonction complète ord().

Liste de paramètres

codepoint

Un entier entre 0 et 255;

Les valeurs en dehors de l'intervalle valide (0..255) seront converties en valeur positive, et se termineront à 255, ce qui est l'équivalent de l'algorithme suivant :

while ($bytevalue < 0) {
    $bytevalue += 256;
}
$bytevalue %= 256;

Valeurs de retour

Retourne une chaîne de caractères d'un seul caractère contenant l'octet spécifié.

Historique

Version	Description
7.4.0	Cette fonction n'accepte plus silencieusement les `codepoint`s non supporté, et casts ces valeurs à `0`.

Exemples

Exemple #1 Exemple avec chr()

<?php
// Suppose que la chaîne sera utilisé en tant que ASCII ou un encodage
// compatible avec celui-ci

$str = "The string ends in escape: ";

// Ajoute un caractère d'échappement à la fin de la chaîne $str
$str .= chr(27);

// Ceci est souvent plus pratique, et réalise la même chose

$str = sprintf("The string ends in escape: %c", 27);
?>

Exemple #2 Comportement de débordement

<?php
echo chr(-159), chr(833), PHP_EOL;
?>

L'exemple ci-dessus va afficher :

aA

Exemple #3 Construite une chaîne UTF-8 à partir d'octet individuel

<?php
$str = chr(240) . chr(159) . chr(144) . chr(152);
echo $str;
?>

L'exemple ci-dessus va afficher :

🐘

Voir aussi

sprintf() - Retourne une chaîne formatée avec le caractère de formatage %c
ord()
» Table ASCII
mb_chr()
IntlChar::chr()

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User Contributed Notes 23 notes

down

perrodin at laposte dot net ¶

20 years ago


Note that if the number is higher than 256, it will return the number mod 256.
For example :
chr(321)=A because A=65(256)

down

voromax ¶

15 years ago


Another quick and short function to get unicode char by its code.

<?php
/**
 * Return unicode char by its code
 *
 * @param int $u
 * @return char
 */
function unichr($u) {
    return mb_convert_encoding('&#' . intval($u) . ';', 'UTF-8', 'HTML-ENTITIES');
}
?>

down

grey - greywyvern - com ¶

19 years ago


I spent hours looking for a function which would take a numeric HTML entity value and output the appropriate UTF-8 bytes.  I found this at another site and only had to modify it slightly; so I don't take credit for this.

<?php function unichr($dec) { 
  if ($dec < 128) { 
    $utf = chr($dec); 
  } else if ($dec < 2048) { 
    $utf = chr(192 + (($dec - ($dec % 64)) / 64)); 
    $utf .= chr(128 + ($dec % 64)); 
  } else { 
    $utf = chr(224 + (($dec - ($dec % 4096)) / 4096)); 
    $utf .= chr(128 + ((($dec % 4096) - ($dec % 64)) / 64)); 
    $utf .= chr(128 + ($dec % 64)); 
  } 
  return $utf;
} ?>

So for example:

<?php

  $str = "Chinese: &#20013;&#25991;";
  $str = preg_replace("/&#(\d{2,5});/e", "unichr($1);", $str);

?>

down

mailderemi at gmail dot com ¶

13 years ago


Here is a sample of encoding and decoding using "chr" and "ord".
<?php
    function Encode($txtData,$Level){
        for ($j = 0;$j<$Level;$j++){
            $tmpStr = '';
            for ($i = 0;$i<strlen($txtData);$i++)
                $tmpStr .= ord(substr(strtoupper($txtData), $i, 1));
            $txtData = $tmpStr;
        }
        return (strlen($Level)).$Level.$txtData;
    }

    function Decode($txtData){
        $intLevel = substr($txtData, 1, substr($txtData, 0, 1));
        $startStr = substr($txtData, substr($txtData, 0, 1)+1, strlen($txtData));
        for ($j = 0;$j<$intLevel;$j++){
            for ($i = 0;$i<strlen($startStr);$i+=2)
                $tmpStr .= chr(intval(substr($startStr, $i, 2)));
            $startStr = $tmpStr;
        
            $tmpStr = "";
        }
        return $startStr;
    }

echo Encode('123',4).'<br>';
echo Decode(Encode('123',5));
?>

down

Noname ¶

2 years ago


<?php

for ($i = 128; $i <= 191; $i++) {
    $str = chr(240) . chr(159) . chr(144) . chr($i);
    echo $str;
}

?>

down

synnus at gmail dot com ¶

9 years ago


// rivencodec 1.0
// encode riverse ascii 1 simple function can encode/decode 
// can use it for secure source with speed encode text

<?php

    function rivencodec($ch,$a=0) {
        while((@$b = $ch[$a++])) { $ch[$a-1] = chr(255-ord($b)); }
        return $ch;
    }
        
    
$zz = rivencodec("abcdefghijklmn");
echo 'encode: ',$zz,'<br/>',PHP_EOL;

$yy = rivencodec($zz);
echo 'decode: ',$yy,'<br/>',PHP_EOL;

?>

down

joeldegan AT yahoo.com ¶

21 years ago


Want terminal colors in command line php scripts?



This should take care of that.

<?



$_colors = array(

        'LIGHT_RED'      => "[1;31m",

        'LIGHT_GREEN'     => "[1;32m",

        'YELLOW'     => "[1;33m",

        'LIGHT_BLUE'     => "[1;34m",

        'MAGENTA'     => "[1;35m",

        'LIGHT_CYAN'     => "[1;36m",

        'WHITE'     => "[1;37m",

        'NORMAL'     => "[0m",

        'BLACK'     => "[0;30m",

        'RED'         => "[0;31m",

        'GREEN'     => "[0;32m",

        'BROWN'     => "[0;33m",

        'BLUE'         => "[0;34m",

        'CYAN'         => "[0;36m",

        'BOLD'         => "[1m",

        'UNDERSCORE'     => "[4m",

        'REVERSE'     => "[7m",



);



function termcolored($text, $color="NORMAL", $back=1){

    global $_colors;

    $out = $_colors["$color"];

    if($out == ""){ $out = "[0m"; }

    if($back){

        return chr(27)."$out$text".chr(27).chr(27)."[0m".chr(27);

    }else{

        echo chr(27)."$out$text".chr(27).chr(27)."[0m".chr(27);

    }//fi

}// end function



echo termcolored("test\n", "BLUE");

?>

down

scott at quinlan dot co dot nz ¶

16 years ago


Secure password generator with a variable maximum amount of symbols.

<?php

function passwdGen($minLength = 8, $maxLength = 12, $maxSymbols = 2)
{
    $symbolCount = 0;

    srand((double)microtime() * 1000003);

    for ($i = 0; $i < rand($minLength, $maxLength); $i++)
    {
        do
        {
            $char = rand(33, 126);

            $symbolCount += $isSymbol = (!in_array($char, range(48, 57)) && !in_array($char, range(65, 90)) && !in_array($char, range(97, 122)));

            if ($symbolCount <= $maxSymbols || !$isSymbol)
            {
                break;
            }
        }
        while (true);

        $passwd = sprintf('%s%c', isset($passwd) ? $passwd : NULL, $char);
    }

    return $passwd;
}

?>

down

happyevil(at)1218.org ¶

23 years ago


Here is a function that's help me find what chr(number) outputs what character quicker than typing out 256 echo tags.



<?php

 function listChr(){

  for ($i = 0; $i < 256; ++$i) {

  static $genNum;

  $genNum++;

  echo "chr($genNum) will output '";

  echo (chr($genNum));

  echo "'< br>\n";

  }

}

listChr();

?>



Another helpful chr is #9, being a tab.  Quite using when making error logs.



 $tab = (chr(9));

 echo "<pre>error{$tab}date{$tab}time</pre>";



 -- HappyEvil

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gjarrige at six-axe dot fr ¶

12 years ago


to remove the ASCII control characters (except "line feed" and "tab") :

$tab_chr = array() ;
for($control = 0; $control < 32; $control++) {
    if ($control != 9 && $control != 10) {
        $tab_chr[]= chr($control) ;
    }
}
$tab_chr[]= chr(127) ;    
$string = str_replace($tab_chr, '', $string);

down

Josh B. ¶

16 years ago


In addition to replacing Microsoft Windows smart quotes, as sgaston demonstrated on 2006-02-13, I replace all other Microsoft Windows characters using suggestions[1] published by character code specialist[2] Jukka Korpela.

<?php
$str = str_replace(chr(130), ',', $str);    // baseline single quote
$str = str_replace(chr(131), 'NLG', $str);  // florin
$str = str_replace(chr(132), '"', $str);    // baseline double quote
$str = str_replace(chr(133), '...', $str);  // ellipsis
$str = str_replace(chr(134), '**', $str);   // dagger (a second footnote)
$str = str_replace(chr(135), '***', $str);  // double dagger (a third footnote)
$str = str_replace(chr(136), '^', $str);    // circumflex accent
$str = str_replace(chr(137), 'o/oo', $str); // permile
$str = str_replace(chr(138), 'Sh', $str);   // S Hacek
$str = str_replace(chr(139), '<', $str);    // left single guillemet
$str = str_replace(chr(140), 'OE', $str);   // OE ligature
$str = str_replace(chr(145), "'", $str);    // left single quote
$str = str_replace(chr(146), "'", $str);    // right single quote
$str = str_replace(chr(147), '"', $str);    // left double quote
$str = str_replace(chr(148), '"', $str);    // right double quote
$str = str_replace(chr(149), '-', $str);    // bullet
$str = str_replace(chr(150), '-', $str);    // endash
$str = str_replace(chr(151), '--', $str);   // emdash
$str = str_replace(chr(152), '~', $str);    // tilde accent
$str = str_replace(chr(153), '(TM)', $str); // trademark ligature
$str = str_replace(chr(154), 'sh', $str);   // s Hacek
$str = str_replace(chr(155), '>', $str);    // right single guillemet
$str = str_replace(chr(156), 'oe', $str);   // oe ligature
$str = str_replace(chr(159), 'Y', $str);    // Y Dieresis
?>

[1] On the use of some MS Windows characters in HTML
http://www.cs.tut.fi/~jkorpela/www/windows-chars.html

[2] Unicode Explained by Jukka Korpela 
http://www.amazon.com/dp/059610121X/

down

tenyou at gmail dot com ¶

20 years ago


When having to deal with parsing an IIS4 or IIS5 metabase dump I wrote a simple function for converting those MS hexidecimal values into their ascii counter parts. Hopefully someone will find use for it.



<?php

function hex_decode($string)  {

        for ($i=0; $i < strlen($string); $i)  {

        $decoded .= chr(hexdec(substr($string,$i,2)));

        $i = (float)($i)+2;

        }

return $decoded;

}

?>

down

-1

darek at module17 dot com ¶

11 years ago


Simple password generation function using sprintf and the %c type specifier; which is the same as chr().

function genPass($len = 8) {
    for ($i=0;$i<=$len;$i++) {
        $passwd = sprintf('%s%c', isset($passwd) ? $passwd : NULL, rand(48, 122));
    }
    return $passwd;
}

down

-1

Kristin ¶

21 years ago


Note that chr(10) is a 'line feed' and chr(13) is a 'carriage return' and they are not the same thing! I found this out while attempting to parse text from forms and text files for inclusion as HTML by replacing all the carriage returns with <BR>'s only to find after many head-scratchings that I should have been looking for line feeds. If anyone can shed some light on what the difference is, please do.



If you're planning on saving text from a form into a database for later display, you'll need to apply the following function so that it gets saved with the proper HTML tags.



<?php

$text = str_replace ( chr(10), "<BR>", $text );

?>



When you want to plug it back into that form for editing you need to convert it back.



<?php

$text = str_replace ( "<BR>", chr(10), $text)

?>



Hope this saves somebody some trouble. :)

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-1

v14t at gmx dot com ¶

10 years ago


argument is automatically converted to integer, so chr('65') and chr(65) would both output the letter A

down

-1

ddawsonNOSPAM at execpc dot com ¶

24 years ago


[Editor's note:



%c is defined as: "Print the character belonging to the ascii code given"



chr() just gives a string, so you need to use %s, even if the string consists of only one character. This is consistent with other languages.

--Jeroen@php.net]





Learn from my mistake:

Do not expect this to work!



<?php

$c_question = chr(63);

$v_out = sprintf("<%cphp\n", $c_question);

//... more stuff being sprintf'd into v_out here ...

$v_out = sprintf("%s%c>\n", $v_out, $c_question);

$v_fp = fopen("foofile", "w");

if ($v_fp)

{

     fwrite($v_fp, $v_out, strlen($v_out));

     fclose($v_fp);

}

?>



When I did this, foofile contained <NUL NUL NUL NUL NUL>.

I spun my wheels quite awhile looking at fputs, fwrite to verify I was calling those functions correctly.

My mistake was using $c_question = chr(63) instead of

$c_question = 63 (correct).  Then everything worked fine.

down

-2

vitkorob ¶

8 years ago


Another quick function to get unicode char by its code.

<?php

function unichr($dec)
{
  if ($dec < 0x80)
  {
    $utf = chr($dec);
  }
  else if ($dec < 0x0800)
  {
    $utf = chr(0xC0 + ($dec >> 6));
    $utf .= chr(0x80 + ($dec & 0x3f));
  }
  else if ($dec < 0x010000)
  {
    $utf = chr(0xE0 + ($dec >> 12));
    $utf .= chr(0x80 + (($dec >> 6) & 0x3f));
    $utf .= chr(0x80 + ($dec & 0x3f));
  }
  else if ($dec < 0x200000)
  {
    $utf = chr(0xF0 + ($dec >> 18));
    $utf .= chr(0x80 + (($dec >> 12) & 0x3f));
    $utf .= chr(0x80 + (($dec >> 6) & 0x3f));
    $utf .= chr(0x80 + ($dec & 0x3f));
  }
  else
  {
    die("UTF-8 character size is more than 4 bytes");
  }

  return $utf;
}

echo unichr(0x263A);

?>

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-2

Ray.Paseur sometimes uses Gmail ¶

5 years ago


I needed to generate an invalid UTF-8 character for testing with JSON.  This did the trick:

<?php
echo 'Bogus UTF-8 character at end' . chr(0xC6) ;

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-2

ibaid at mail dot ru ¶

6 years ago


string mb_chr ( int $cp [, string $encoding ] )
Parameter List:
cp - character code (in decimal notation)
encoding - encoding (UTF-8, ASCII and so on)

We get the letter 'Ж'  from the encoding UTF-8:

$sim = mb_chr(0x0416, 'UTF-8');
echo $sim; // Ж

Get the character '}' from the encoding ASCII:

$sim = mb_chr(125, 'ASCII');
echo $sim ; // }

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-4

darkodemon at gmail dot com ¶

17 years ago


chr() with unicode support

<?php

function uchr ($codes) {
    if (is_scalar($codes)) $codes= func_get_args();
    $str= '';
    foreach ($codes as $code) $str.= html_entity_decode('&#'.$code.';',ENT_NOQUOTES,'UTF-8');
    return $str;
}

echo uchr(23383); echo '<br/>';
echo uchr(23383,215,23383); echo '<br/>';
echo uchr(array(23383,215,23383,215,23383)); echo '<br/>';

?>

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-3

sinfocol at sinfocol dot org ¶

15 years ago


The function chr() also accepts negative numbers as an ascii code, so chr(-number) is equal to chr((number%256)+256).

And for ascii code higher than 255 is chr(number%256)



We can test with a little script

<?php

    for($i=-300; $i<300; $i++){

        echo "Ascii $i\t" . ord(chr($i)) . "\n";

    }

?>

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-5

lingtalfi - at - somewhere ¶

9 years ago


It seems that php uses the table from here: http://ascii-code.com/ 
(and not from here: http://www.asciitable.com/ as suggested in the documentation) for codes from 128 to 255.

<?php
for ($i = 32; $i <= 255; $i++) {
    echo chr($i);
}
?>

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-3

gfour ¶

5 years ago


I was looking for a simple method to construct excel like column identifiers e.g: A B .... AA AB AC etc, using chr() and modulo, but there is magic...
https://www.php.net/manual/en/language.operators.increment.php

So, this also works
<?php
$p = chr(65);      // or simply $p = 'A';
for ($i = 1; $i < 53; $i++){
    echo $p++ . " - ";
    if ($i % 10 == 0) echo '</br>';
}
?>

Gives
A - B - C - D - E - F - G - H - I - J -
K - L - M - N - O - P - Q - R - S - T -
U - V - W - X - Y - Z - AA - AB - AC - AD -
AE - AF - AG - AH - AI - AJ - AK - AL - AM - AN -
AO - AP - AQ - AR - AS - AT - AU - AV - AW - AX -
AY - AZ -

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