Two methods for determining character encoding in PHP

I would like to introduce two methods for PHP to determine the character encoding. One is to use the function mb_detect_encoding that comes with PHP, and the other is to write a function yourself to handle it. Friends in need, come and take a look.

Method 1, use mb_detect_encoding function.

<?php
$str=”程序员之家，欢迎大家的光临。”;
echo mb_detect_encoding($str);
?>

Method 2, custom function.

<?php
function chkbm($string){
    $bm = array(‘ASCII’, ‘GBK’, ‘UTF-8′);
    foreach($bm as $c){
        if( $string === iconv(‘UTF-8′, $c, iconv($c, ‘UTF-8′, $string))){//转换编码后是不是相等
            return $c;
        }
    }
    return null;
}
?>

How to choose? Smart one, you decide, ha~~~