字符串函数
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ord

(PHP 4, PHP 5)

ord — 返回字符的 ASCII 码值

说明

int ord ( string $string )

返回字符串 string 第一个字符的 ASCII 码值。

该函数是 chr() 的互补函数。

参数

string

一个字符。

返回值

返回整型的 ASCII 码值。

范例

Example #1 ord() 范例

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

参见

字符串函数
在线手册：中文 英文
PHP手册
PHP手册 - N: 返回字符的 ASCII 码值

用户评论:

znaeff at mail dot ru (06-Oct-2011 05:36)

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.

Anonymous (05-Apr-2011 01:49)

i need put utf8 hungarian "abc" into html id attribute, but id not contain non-ascii chars (like á, ?, ?), 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','?', 'ó','?','?','?','?','?','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
?: 195137
ó: 195179
?: 195147
?: 195182
?: 195150
?: 197145
?: 197144
ú: 195186

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

manixrock(hat)gmail(doink)com (03-Jun-2010 04:14)

For anyone having trouble trying to detect the encoding of a string because PHP provides no easy way to see the characters (and byte values) of a string, here's a function that returns the characters and byte values for the ASCII and UTF-8 encodings:

<?php
function hex_chars($data) {
    $mb_chars = '';
    $mb_hex = '';
    for ($i=0; $i<mb_strlen($data, 'UTF-8'); $i++) {
        $c = mb_substr($data, $i, 1, 'UTF-8');
        $mb_chars .= '{'. ($c). '}';
       
        $o = unpack('N', mb_convert_encoding($c, 'UCS-4BE', 'UTF-8'));
        $mb_hex .= '{'. hex_format($o[1]). '}';
    }
    $chars = '';
    $hex = '';
    for ($i=0; $i<strlen($data); $i++) {
        $c = substr($data, $i, 1);
        $chars .= '{'. ($c). '}';
        $hex .= '{'. hex_format(ord($c)). '}';
    }
    return array(
        'data' => $data,
        'chars' => $chars,
        'hex' => $hex,
        'mb_chars' => $mb_chars,
        'mb_hex' => $mb_hex,
    );
}
function hex_format($o) {
    $h = strtoupper(dechex($o));
    $len = strlen($h);
    if ($len % 2 == 1)
        $h = "0$h";
    return $h;
}
?>

regalia at umail dot ucsb dot edu (26-Jan-2009 11:54)

Make sure that the parameter you are passing to the ord function is a string.

<?php
$num = 12345;

// Incorrect usage of square bracket notation
if(ord($num[0]) == 0)  {
    echo "Not a valid ASCII character";
}

// Using the substr method will account for any data type
if(ord(substr($num,0,1)) == 0) {
    echo "Not a valid ASCII character";
}

?>

darien at etelos dot com (19-Jan-2007 07:27)

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);
}

?>

S.N.O.W.M.A.N.-X (28-Sep-2006 08:47)

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;   
}
?>

phil (at) pchowtos (dot) co (dot) uk (18-Jul-2006 06:51)

You can use the following function to generate a random string between the lengths of $x and $y...

<?php
$x = 1;  //minimum length
$y = 10;  //maximum length

$len = rand($x,$y);  //get a random string length

for ($i = 0; $i < $len; $i++) {  //loop $len no. of times
   $whichChar = rand(1,3);  //choose if its a caps, lcase or num
   if ($whichChar == 1) { //it's a number
      $string .= chr(rand(48,57));  //randomly generate a num
   }
   elseif ($whichChar == 2) { //it's a small letter
      $string .= chr(rand(65,90));  //randomly generate an lcase
   }
   else { //it's a capital letter
      $string .= chr(rand(97,122));  //randomly generate a ucase
   }
}

echo $string;  //echo out the generated string
?>

erdem at a1tradenetwork dot com (17-May-2006 07:16)

I have a new characters table. i want send it below that.

<?php
$color = "#f1f1f1";
echo "<center>";
echo "<h1>From 32 To 255 Characters Table</h1>";
echo "</center>";
echo "<table border=\"0\" style=\"font-family:verdana;font-size:11px;\"".
     " align=\"center\" width=\"800\"><tr style=\"font-weight:bold;\"  ".
     "bgcolor=\"#99cccc\">".
     "<td width=\"15\">DEC</td><td width=\"15\">OCT</td>".
     "<td width=\"15\">HEX</td><td width=\"15\">CHR</td>".
    
     "<td width=\"15\">DEC</td><td width=\"15\">OCT</td>".
     "<td width=\"15\">HEX</td><td width=\"15\">CHR</td>".
    
     "<td width=\"15\">DEC</td><td width=\"15\">OCT</td>".
     "<td width=\"15\">HEX</td><td width=\"15\">CHR</td>".
    
     "<td width=\"15\">DEC</td><td width=\"15\">OCT</td>".
     "<td width=\"15\">HEX</td><td width=\"15\">CHR</td>".
    
     "<td width=\"15\">DEC</td><td width=\"15\">OCT</td>".
     "<td width=\"15\">HEX</td><td width=\"15\">CHR</td>".
    
     "<td width=\"15\">DEC</td><td width=\"15\">OCT</td>".
     "<td width=\"15\">HEX</td><td width=\"15\">CHR</td>".
    
    
     "</tr><tr>";
$ii = 0;
for ($i=32;$i<=255;$i++){
    $char = chr($i);   
    $dec  = ord($char);
    if ($i == "32") {
        $char = "Space";
    }
    echo "<td style=\"background-color:$color;width:15px;\">".
         $dec."</td>\n<td style=\"background-color:$color;".
         "width:15px;text-align:left;\">".decoct($dec)."</td>\n".
         "<td style=\"background-color:$color;width:15px;".
         "text-align:left;\">".dechex($dec)."</td>\n ".
         "<td style=\"background-color:$color;width:15px;".
         "text-align:left;\"><b>".$char."</b></td>\n ";

    if (($ii % 6) == 5) {
    echo "</tr>\n<tr>\n";
   
    }
  
   if (($ii % 2) == 1) {
         $color = "#f1f1f1";
    }else {
         $color = "#ffffcc";
    }
   
    $ii++;
}
echo "</tr></table>";
?>

Matthew Flint (31-Oct-2005 10:59)

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;
}
?>

(01-Mar-2005 02:12)

Function using ord() to strip out garbage characters and punctuation from a string. This is handy when trying to be smart about what an input is "trying" to be..
<?php

function cleanstr($string){
    $len = strlen($string);
    for($a=0; $a<$len; $a++){
        $p = ord($string[$a]);
        # chr(32) is space, it is preserved..
        (($p > 64 && $p < 123) || $p == 32) ? $ret .= $string[$a] : $ret .= "";
    }
    return $ret;
}

?>

jacobfri at skydebanen dot net (04-Jun-2004 01:10)

Just to get things straight about which character table ord() and chr() uses.
The range 128-255 is _not_ equivalent with the widely used extended ASCII-table, like the one described in www.asciitable.com. The actual equivalent is the 128-255 range of Unicode.
That's a good thing, because then ord() and chr() is compatible with javascript, and any other language that uses Unicode.
But it's rather nice to know it, and the description of ord() is kind of misleading, when it only refers to www.asciitable.com.

v0rbiz at yahoo dot com (29-May-2004 12:15)

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;
}
?>

arjini at mac dot com (19-Mar-2004 07:49)

If you're looking to provide bare bones protection to email addresses posted to the web try this:

<?php
$string = 'arjini@mac.com';
for($i=0;$i<strlen($string);++$i){
    $n = rand(0,1);
    if($n)
        $finished.='&#x'.sprintf("%X",ord($string{$i})).';';
    else
        $finished.='&#'.ord($string{$i}).';';
}
echo $finished;
?>

This randomly encodes a mix of hex and oridinary HTML entities for every character in the address. Note that a decoding mechanism for this could probably be written just as easily, so eventually the bots will be able to cut through this like butter, but for now, it seems like most harvesters are only looking for non-hex html entities.