PHP之string之chr()函数使用
chr
- (PHP 4, PHP 5, PHP 7)
- chr — Return a specific character
- chr — 返回指定的字符
Description
string chr ( int $ascii )
//Returns a one-character string containing the character specified by ascii.
//返回相对应于 ascii 所指定的单个字符。
//This function complements ord().
//此函数与 ord() 是互补的。
Parameters
ascii
-
The extended ASCII code.
-
Ascii 码。
-
Values outside the valid range (0..255) will be bitwise and'ed with 255, which is equivalent to the following algorithm:
while ($ascii < 0) {
$ascii += 256;
}
$ascii %= 256;
Return Values
- Returns the specified character.
- 返回规定的字符。
Examples
<?php
/**
* Created by PhpStorm.
* User: zhangrongxiang
* Date: 2018/2/15
* Time: 下午6:56
*/
for ( $i = 65; $i < 127; $i ++ ) {
echo chr( $i ) . ' ';
if ( $i % 10 == 0 ) {
echo PHP_EOL;
}
}
/*
* 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
* [ \ ] ^ _ ` 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 { | } ~
*/
echo PHP_EOL;
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;
}
//中
echo unichr( 20013 ) . PHP_EOL;
//A
echo chr( 321 ) . PHP_EOL;//A 256 + 65 = 321
function genPass( $len = 8 ) {
$passwd = '';
for ( $i = 0; $i <= $len; $i ++ ) {
$passwd = sprintf( '%s%c', isset( $passwd ) ? $passwd : null, rand( 48, 122 ) );
}
return $passwd;
}
//vuTR<oUn;
echo genPass( 8 ) . PHP_EOL;
function unichr2( $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;
}
function unichr3( $u ) {
return mb_convert_encoding( '&#' . intval( $u ) . ';', 'UTF-8', 'HTML-ENTITIES' );
}
echo unichr( 0x263A ) . PHP_EOL;//☺
echo unichr2( 0x263A ) . PHP_EOL;//☺
echo unichr3( 0x263A ) . PHP_EOL;//☺
echo unichr( 0x263B ) . PHP_EOL;//☻
echo unichr2( 0x263B ) . PHP_EOL;//☻
echo unichr( 20013 ) . PHP_EOL;//中
echo unichr2( 20013 ) . PHP_EOL;//中
echo unichr3( 20013 ) . PHP_EOL;//中
