详解PHP中mb_strpos的使用

//Performs a multi-byte safe strpos() operation based on number of characters. The first character's position is 0,the second character position is 1,and so on.
// 基于字符数执行一个多字节安全的 strpos() 操作。 第一个字符的位置是 0，第二个字符的位置是 1，以此类推。

$str = "Hello World! Hello PHP";
$pos = mb_strpos( $str,"Hello",mb_internal_encoding() );
echo $pos . PHP_EOL;//0
$pos = mb_strpos( $str,2,mb_internal_encoding() );
echo $pos . PHP_EOL;//13

function mb_str_replace( $haystack,$search,$replace,$offset = 0,$encoding = 'auto' ) {
$len_sch = mb_strlen( $search,$encoding );
$len_rep = mb_strlen( $replace,$encoding );

while ( ( $offset = mb_strpos( $haystack,$offset,$encoding ) ) !== false ) {
$haystack = mb_substr( $haystack,$encoding )
. $replace
. mb_substr( $haystack,$offset + $len_sch,$le = mb_strlen( $haystack ) - mb_strlen( $search ) + mb_strlen( $replace ),$encoding );
//echo $le.PHP_EOL;
$offset = $offset + $len_rep;
if ( $offset > mb_strlen( $haystack,$encoding ) ) {
break;
}
}

return $haystack;
}

$replace = mb_str_replace( "hello world !hello world !hello world !hello world !","hello","hi" );
echo $replace . PHP_EOL; //hi world !hi world !hi world !hi world !

//hi PHP !hi PHP !hi PHP !hi PHP !
echo mb_str_replace( $replace,"world","PHP" ) . PHP_EOL;
echo mb_str_replace( $replace," ","-" ) . PHP_EOL;

//PHP是世界上最好的语言😂😂😂😂😂😂
echo mb_str_replace( "PHP是世界上最好的语言😄😄😄😄😄😄",'😄','😂',mb_internal_encoding() ) . PHP_EOL;
echo mb_str_replace( "112233445566",'22','00' ) . PHP_EOL;//110033445566
echo mb_str_replace( '😄😄😄😄','😫1',mb_internal_encoding() ) . PHP_EOL;
echo mb_str_replace( '1111','111','0',1 ) . PHP_EOL;//10
echo mb_strlen( '😄😄😄😄' ) . PHP_EOL;//4

//代码开发代码
echo mb_str_replace( '软件开发软件','软件','代码',mb_internal_encoding()) . PHP_EOL;
//代码开发 //todo??
echo mb_str_replace( '软件开发软件','代码' ) . PHP_EOL;