int ord ( string $string )//Returns the ASCII value of the first character of string.//返回字符串 string 第一个字符的 ASCII 码值。//This function complements chr().//该函数是 chr() 的互补函数。

<?php/** * Created by PhpStorm. * User: zhangrongxiang * Date: 2018/2/18 * Time: 下午9:43 */$str = 'abcdef';for ( $i = 0; $i < strlen( $str ); $i ++ ) { ???echo $str[ $i ] . ' : ' . ord( $str{$i} ) . PHP_EOL;}/* * a : 97 * b : 98 * c : 99 * d : 100 * e : 101 * f : 102 */echo ord( 'a' ) . PHP_EOL;//97echo ord( 'b' ) . PHP_EOL;//98function ordutf8( $string, &$offset ) { ???$code ???????= ord( substr( $string, $offset, 1 ) ); ???$bytesnumber = 0; ???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 $code;}$text ??= "中国??";$offset = 0;while ( $offset >= 0 ) { ???//0: 20013 ???//3: 22269 ???//6: 128516 ???echo $offset . ": " . ordutf8( $text, $offset ) . PHP_EOL;}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;}echo uniord( "中" ) . PHP_EOL;//20013echo uniord( "国" ) . PHP_EOL;//22269//errorecho uniord( '??' ) . PHP_EOL;//63