How PHP intercepts the characters before commas

Aaaaa,bbbbbbb,ccccc
First determine if there is a comma (do not know if this step is required, because there is no comma in the case), if there is a truncation of the first comma before the character (without inclusion of commas)

Reply to discussion (solution)

$email = ' name@example.com ';
$domain = Strstr ($email, ' @ ');
Echo $domain; Print @example. com

$user = Strstr ($email, ' @ ', true); From PHP 5.3.0 onwards
Echo $user; Print Name

$str = ' AAAAA,BBBBBBB,CCCCC ', if (Strpos ($str, ', ')) {Preg_match ('/([^,]+?),/I ', $str, $match);} Print_r ($match [1]);/*aaaaa*/

$s = ' AAAAA,BBBBBBB,CCCCC '; Echo strtok ($s, ', ');

$string = ' 111a,111 ';            $flag = Strpos ($string, ', ');            if ($flag!== FALSE) {                $arr = explode (', ', $string);                echo $arr [0];            } else{                echo $string;            }

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