chr

(PHP 4, PHP 5, PHP 7)

chr返回指定的字符

说明

string chr ( int $ascii )

返回相对应于 ascii 所指定的单个字符。

此函数与 ord() 是互补的。

参数

ascii

Ascii 码。

返回值

返回规定的字符。

范例

Example #1 chr() 例子

<?php
$str 
"The string ends in escape: ";
$str .= chr(27); /* 在 $str 后边增加换码符 */

/* 通常这样更有用 */

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

参见

add a note add a note

User Contributed Notes 21 notes

up
17
perrodin at laposte dot net
14 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)
up
15
voromax
9 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');
}
?>
up
4
grey - greywyvern - com
13 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);

?>
up
3
gjarrige at six-axe dot fr
6 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);
up
5
joeldegan AT yahoo.com
15 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");
?>
up
2
vitkorob
2 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);

?>
up
4
darkodemon at gmail dot com
11 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/>';

?>
up
3
happyevil(at)1218.org
17 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
up
3
Josh B.
10 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/
up
1
synnus at gmail dot com
3 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;

?>
up
1
v14t at gmx dot com
4 years ago
argument is automatically converted to integer, so chr('65') and chr(65) would both output the letter A
up
2
ddawsonNOSPAM at execpc dot com
18 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.
up
2
darek at module17 dot com
5 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;
}
up
1
Kristin
15 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. :)
up
0
ibaid at mail dot ru
5 months 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 ; // }
up
0
lingtalfi - at - somewhere
3 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);
}
?>
up
0
mailderemi at gmail dot com
7 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));
?>
up
0
sinfocol at sinfocol dot org
9 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";
    }
?>
up
0
scott at quinlan dot co dot nz
9 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;
}

?>
up
0
sarabas at itstudio dot pl
13 years ago
The following function helped me to generate ascii-only usernames from firstname/lastname containing iso-8859-2 characters. The convertion array was based on contents of 'man iso-8859-2'.

Example: iso2ascii("b&#322;a&#380;ej.&#378;d&#378;b&#322;o") returns "blazej.zdzblo"

<?php
function iso2ascii($str) {
$arr=array(
 
chr(161)=>'A', chr(163)=>'L', chr(165)=>'L', chr(166)=>'S', chr(169)=>'S',
 
chr(170)=>'S', chr(171)=>'T', chr(172)=>'Z', chr(174)=>'Z', chr(175)=>'Z',
 
chr(177)=>'a', chr(179)=>'l', chr(181)=>'l', chr(182)=>'s', chr(185)=>'s',
 
chr(186)=>'s', chr(187)=>'t', chr(188)=>'z', chr(190)=>'z', chr(191)=>'z',
 
chr(192)=>'R', chr(193)=>'A', chr(194)=>'A', chr(195)=>'A', chr(196)=>'A',
 
chr(197)=>'L', chr(198)=>'C', chr(199)=>'C', chr(200)=>'C', chr(201)=>'E',
 
chr(202)=>'E', chr(203)=>'E', chr(204)=>'E', chr(205)=>'I', chr(206)=>'I',
 
chr(207)=>'D', chr(208)=>'D', chr(209)=>'N', chr(210)=>'N', chr(211)=>'O',
 
chr(212)=>'O', chr(213)=>'O', chr(214)=>'O', chr(216)=>'R', chr(217)=>'U',
 
chr(218)=>'U', chr(219)=>'U', chr(220)=>'U', chr(221)=>'Y', chr(222)=>'T',
 
chr(223)=>'s', chr(224)=>'r', chr(225)=>'a', chr(226)=>'a', chr(227)=>'a',
 
chr(228)=>'a', chr(229)=>'l', chr(230)=>'c', chr(231)=>'c', chr(232)=>'c',
 
chr(233)=>'e', chr(234)=>'e', chr(235)=>'e', chr(236)=>'e', chr(237)=>'i',
 
chr(238)=>'i', chr(239)=>'d', chr(240)=>'d', chr(241)=>'n', chr(242)=>'n',
 
chr(243)=>'o', chr(244)=>'o', chr(245)=>'o', chr(246)=>'o', chr(248)=>'r',
 
chr(249)=>'u', chr(250)=>'u', chr(251)=>'u', chr(252)=>'u', chr(253)=>'y',
 
chr(254)=>'t'
);
return
strtr($str,$arr);
}
?>
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-2
tenyou at gmail dot com
14 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;
}
?>
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