If you are looking for PHP's strstr function in Javascript you can use following javascript function,
Reference : http://phpjs.org/functions/strstr/
function strstr(haystack, needle, bool) { var pos = 0; haystack += ''; pos = haystack.indexOf(needle); if (pos == -1) { return false; } else { if (bool) { return haystack.substr(0, pos); } else { return haystack.slice(pos); } } }
Reference : http://phpjs.org/functions/strstr/