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)
(PHP 4, PHP 5, PHP 7, PHP 8)
chr — 从数字生成单字节字符串
返回单字符字符串，包含将 codepoint 作为无符号整数解释的指定字符。
这可用于在一种单字节编码（像是 ASCII、ISO-8859 或 Windows 1252）中通过传递想要的字符在编码映射表中的位置来创建单字符字符串。但是，注意此函数并不清楚任何字符串编码，特别是无法通过传递一个 Unicode 码位值来生成多字节编码（像是 UTF-8 或 UTF-16）字符串。
此函数与 ord() 互补。
codepoint一个介于 0 与 255 之间的整数。
超过有效范围（0..255）的值将和 255“按位与”，与以下算法等效：
while ($bytevalue < 0) {
$bytevalue += 256;
}
$bytevalue %= 256;包含指定字节的单字符字符串。
| 版本 | 说明 |
|---|---|
| 7.4.0 |
此函数不再静默接受不支持的 codepoint，并会将它们转为 0。
|
示例 #1 chr() 例子
<?php
// 假设该字符串将被作为 ASCII 或是一个与 ASCII 兼容的编码使用
$str = "The string ends in escape: ";
$str .= chr(27); /* 在 $str 末尾添加一个转义字符 */
/* 通常这样更有用 */
$str = sprintf("The string ends in escape: %c", 27);
?>示例 #2 溢出行为
<?php
echo chr(-159), chr(833), PHP_EOL;
?>以上示例会输出：
aA
示例 #3 从单个字节构建 UTF-8 字符串
<?php
$str = chr(240) . chr(159) . chr(144) . chr(152);
echo $str;
?>以上示例会输出：
%cNote that if the number is higher than 256, it will return the number mod 256.
For example :
chr(321)=A because A=65(256)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($u) . ';', 'UTF-8', 'HTML-ENTITIES');
}
?>I spent hours looking for a function which would take a numeric HTML entity value and output the appropriate UTF-8 bytes. I found this at another site and only had to modify it slightly; so I don't take credit for this.
<?php function unichr($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: 中文";
$str = preg_replace("/&#(\d{2,5});/e", "unichr($1);", $str);
?>Here is a sample of encoding and decoding using "chr" and "ord".
<?php
function Encode($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 $startStr;
}
echo Encode('123',4).'<br>';
echo Decode(Encode('123',5));
?><?php
for ($i = 128; $i <= 191; $i++) {
$str = chr(240) . chr(159) . chr(144) . chr($i);
echo $str;
}
?>// rivencodec 1.0
// encode riverse ascii 1 simple function can encode/decode
// can use it for secure source with speed encode text
<?php
function rivencodec($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;
?>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");
?>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, '', $string);When having to deal with parsing an IIS4 or IIS5 metabase dump I wrote a simple function for converting those MS hexidecimal values into their ascii counter parts. Hopefully someone will find use for it.
<?php
function hex_decode($string) {
for ($i=0; $i < strlen($string); $i) {
$decoded .= chr(hexdec(substr($string,$i,2)));
$i = (float)($i)+2;
}
return $decoded;
}
?>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', $str); // Y Dieresis
?>
[1] On the use of some MS Windows characters in HTML
http://www.cs.tut.fi/~jkorpela/www/windows-chars.html
[2] Unicode Explained by Jukka Korpela
http://www.amazon.com/dp/059610121X/Secure password generator with a variable maximum amount of symbols.
<?php
function passwdGen($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 $passwd;
}
?>Here is a function that's help me find what chr(number) outputs what character quicker than typing out 256 echo tags.
<?php
function listChr(){
for ($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{$tab}time</pre>";
-- HappyEvilI needed to generate an invalid UTF-8 character for testing with JSON. This did the trick:
<?php
echo 'Bogus UTF-8 character at end' . chr(0xC6) ;Another quick function to get unicode char by its code.
<?php
function unichr($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 $utf;
}
echo unichr(0x263A);
?>Simple password generation function using sprintf and the %c type specifier; which is the same as chr().
function genPass($len = 8) {
for ($i=0;$i<=$len;$i++) {
$passwd = sprintf('%s%c', isset($passwd) ? $passwd : NULL, rand(48, 122));
}
return $passwd;
}[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.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. :)argument is automatically converted to integer, so chr('65') and chr(65) would both output the letter Astring 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 $sim ; // }It seems that php uses the table from here: http://ascii-code.com/
(and not from here: http://www.asciitable.com/ as suggested in the documentation) for codes from 128 to 255.
<?php
for ($i = 32; $i <= 255; $i++) {
echo chr($i);
}
?>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/>';
?>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 -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";
}
?>