ord

(PHP 4, PHP 5, PHP 7)

ord — Return ASCII value of character

Description

int ord ( string $string )

Returns the ASCII value of the first character of string.

This function complements chr().

Parameters

string: A character.

Return Values

Returns the ASCII value as an integer.

Examples

Example #1 ord() example


<?php
$str = "\n";
if (ord($str) == 10) {
    echo "The first character of \$str is a line feed.\n";
}
?>

User Contributed Notes

arglanir+phpnet at gmail dot com

3 years ago


As ord() doesn't work with utf-8, and if you do not have access to mb_* functions, the following function will work well:
<?php
function ordutf8($string, &$offset) {
    $code = ord(substr($string, $offset,1)); 
    if ($code >= 128) {        //otherwise 0xxxxxxx
        if ($code < 224) $bytesnumber = 2;                //110xxxxx
        else if ($code < 240) $bytesnumber = 3;        //1110xxxx
        else if ($code < 248) $bytesnumber = 4;    //11110xxx
        $codetemp = $code - 192 - ($bytesnumber > 2 ? 32 : 0) - ($bytesnumber > 3 ? 16 : 0);
        for ($i = 2; $i <= $bytesnumber; $i++) {
            $offset ++;
            $code2 = ord(substr($string, $offset, 1)) - 128;        //10xxxxxx
            $codetemp = $codetemp*64 + $code2;
        }
        $code = $codetemp;
    }
    $offset += 1;
    if ($offset >= strlen($string)) $offset = -1;
    return $code;
}
?>
$offset is a reference, as it is not easy to split a utf-8 char-by-char. Useful to iterate on a string:
<?php
$text = "abcàêß€abc";
$offset = 0;
while ($offset >= 0) {
    echo $offset.": ".ordutf8($text, $offset)."\n";
}
/* returns:
0: 97
1: 98
2: 99
3: 224
5: 234
7: 223
9: 8364
12: 97
13: 98
14: 99
*/
?>
Feel free to adapt my code to fit your needs.

rowan dot collins at cwtdigital dot com

2 years ago


Regarding character sets, and whether or not this is "ASCII". Firstly, there is no such thing as "8-bit ASCII", so if it were ASCII it would only ever return integers up to 127. 8-bit ASCII-compatible encodings include the ISO 8859 family of encodings, which map various common characters to the values from 128 to 255. UTF-8 is also designed so that characters representable in 7-bit ASCII are coded the same; byte values higher than 127 in a UTF-8 string represent the beginning of a multi-byte character.

In fact, like most of PHP's string functions, this function isn't doing anything to do with character encoding at all - it is just interpreting a binary byte from a string as an unsigned integer. That is, ord(chr(200)) will always return 200, but what character chr(200) *means* will vary depending on what character encoding it is *interpreted* as part of (e.g. during display).

A technically correct description would be "Returns an integer representation of the first byte of a string, from 0 to 255. For single-byte encodings such as (7-bit) ASCII and the ISO 8859 family, this will correspond to the first character, and will be the position of that character in the encoding's mapping table. For multi-byte encodings, such as UTF-8 or UTF-16, the byte may not represent a complete character."

The link to asciitable.com should also be replaced by one which explains what character encoding it is displaying, as "Extended ASCII" is an ambiguous and misleading name.

darien at etelos dot com

9 years ago


I found I wanted to sanitize a string for certain ASCII/ANSI characters, but to leave unicode alone. Since ord() breaks on processing unicode, I drew these two functions up to help with a saniziter which looked at ordinal values. (Finding "pack" and "unpack" was much better than my own powers-of-256 code.)

<?php

/* 
    By Darien Hager, Jan 2007... Use however you wish, but please
    please give credit in source comments. 
    
    Change "UTF-8" to whichever encoding you are expecting to use.
*/
function ords_to_unistr($ords, $encoding = 'UTF-8'){
    // Turns an array of ordinal values into a string of unicode characters
    $str = '';
    for($i = 0; $i < sizeof($ords); $i++){
        // Pack this number into a 4-byte string
        // (Or multiple one-byte strings, depending on context.)                
        $v = $ords[$i];
        $str .= pack("N",$v);
    }
    $str = mb_convert_encoding($str,$encoding,"UCS-4BE");
    return($str);            
}

function unistr_to_ords($str, $encoding = 'UTF-8'){        
    // Turns a string of unicode characters into an array of ordinal values,
    // Even if some of those characters are multibyte.
    $str = mb_convert_encoding($str,"UCS-4BE",$encoding);
    $ords = array();
    
    // Visit each unicode character
    for($i = 0; $i < mb_strlen($str,"UCS-4BE"); $i++){        
        // Now we have 4 bytes. Find their total
        // numeric value.
        $s2 = mb_substr($str,$i,1,"UCS-4BE");                    
        $val = unpack("N",$s2);            
        $ords[] = $val[1];                
    }        
    return($ords);
}

?>

znaeff at mail dot ru

4 years ago


I've found that variant with 

unpack('N', mb_convert_encoding($c, 'UCS-4BE', 'UTF-8'));

is VERY-VERY slow.

Remember this when process strings longer than 1K.

xB1N4RYx

3 years ago


return the chars as a sql char() string

<?php
function AsciiToInt($char){
$success = "";
    if(strlen($char) == 1)
        return "char(".ord($char).")";
    else{
        for($i = 0; $i < strlen($char); $i++){
            if($i == strlen($char) - 1)
                $success = $success.ord($char[$i]);
            else
                $success = $success.ord($char[$i]).",";
        }
        return "char(".$success.")";
    }
}
echo AsciiToInt("<br>");//outputs char(60,98,114,62)
?>

S.N.O.W.M.A.N.-X

9 years ago


Well, i was thinking about a method to hash a string with md5 in a loose way, so md5("HELLO") isn't the same like md5("Hello"), even, i my case, it is about cd-titles i got submitted by users. So i made some function transforming my string to right what i want



Thisone is the "call" function returning the "loose hash".

It will get only the chars of a string, make them to uppercase and then hash with md5.



<?php

function loosehash($string){

    return md5(strtoupper(onlyChars($string)));

}

?>



Thisone is moving through a string like a chararray and check for the asciivalues, you can edit the values and condition to fit your needs



<?php

function onlyChars($string){

    $strlength = strlen($string);

    $retString = "";

    for($i = 0; $i < $strlength; $i++){

        if((ord($string[$i]) >= 48 && ord($string[$i]) <= 57) ||

        (ord($string[$i]) >= 65 && ord($string[$i]) <= 90) ||

        (ord($string[$i]) >= 97 && ord($string[$i]) <= 122)){

            $retString .= $string[$i];

        }

    }

    

    echo $retString;    

}

?>

marc at kryn dot org

3 years ago


Since this function is not utf-8/unicode ready, you can use following code to get the hex or dec representation of a character.



<?php

mb_internal_encoding("UTF-8");

$string = '↗Զ';

$char = mb_substr($string, 0, 1);

var_dump(bin2hex($char)); //hex

var_dump(hexdec(bin2hex($char))); //decimal

?>



returns:



string(6) "e28697"

int(14845591)

v0rbiz at yahoo dot com

11 years ago


I did not found a unicode/multibyte capable 'ord' function, so...



<?php

function uniord($u) {

    $k = mb_convert_encoding($u, 'UCS-2LE', 'UTF-8');

    $k1 = ord(substr($k, 0, 1));

    $k2 = ord(substr($k, 1, 1));

    return $k2 * 256 + $k1;

}

?>

Matthew Flint

10 years ago


I wrote the following function to clean illegal characters from input strings.

(Background: I have a php-based news website. People were writing articles in MS Word, then copy-and-pasting the text into the website. Word uses non-standard characters for opening and closing quotes and double-quotes, and for "..." - and this was resulting in articles on the website that failed XHTML validation)

<?php
function clean_string_input($input)
{
    $interim = strip_tags($input);

    if(get_magic_quotes_gpc())
    {
        $interim=stripslashes($interim);
    }

    // now check for pure ASCII input
    // special characters that might appear here:
    //   96: opening single quote (not strictly illegal, but substitute anyway)
    //   145: opening single quote
    //   146: closing single quote
    //   147: opening double quote
    //   148: closing double quote
    //   133: ellipsis (...)
    //   163: pound sign (this is safe, so no substitution required)
    // these can be substituted for safe equivalents
    $result = '';
    for ($i=0; $i<strlen($interim); $i++)
    {
        $char = $interim{$i};
        $asciivalue = ord($char);
        if ($asciivalue == 96)
        {
            $result .= '\\'';
        }
        else if (($asciivalue > 31 && $asciivalue < 127) ||
                 ($asciivalue == 163) || // pound sign
                 ($asciivalue == 10) || // lf
                 ($asciivalue == 13)) // cr
        {
            // it's already safe ASCII
            $result .= $char;
        }
        else if ($asciivalue == 145) // opening single quote
        {
            $result .= '\\'';
        }
        else if ($asciivalue == 146) // closing single quote
        {
            $result .= '\\'';
        }
        else if ($asciivalue == 147) // opening double quote
        {
            $result .= '"';
        }
        else if ($asciivalue == 148) // closing double quote
        {
            $result .= '"';
        }
        else if ($asciivalue == 133) // ellipsis
        {
            $result .= '...';
        }
    }

    return $result;
}
?>

Anonymous

5 years ago


i need put utf8 hungarian "abc" into html id attribute, but id not contain non-ascii chars (like á, ő, ű), and not to begin a number.

<?php

function utfCharToNumber($char) {
    $i = 0;
    $number = '';
    while (isset($char{$i})) {
        $number.= ord($char{$i});
        ++$i;
        }
    return $number;
    }

// example use
foreach (array('a','A','b','B','c','C','e','é','É', 'ó','Ó','ö','Ö','ő','Ő','ú') as $d) {
    echo $d,': ',utfCharToNumber($d),"\n";
    }
?>

output:
a: 97
A: 65
b: 98
B: 66
c: 99
C: 67
e: 101
é: 195169
É: 195137
ó: 195179
Ó: 195147
ö: 195182
Ö: 195150
ő: 197145
Ő: 197144
ú: 195186

i generated the folowing ids:
"char-97", "char-65", "char-98" ...

ord

Description

Parameters

Return Values

Examples

See Also

User Contributed Notes