about str_repeat()

An error was reported when I try these code: $level = .....................; echo str_repeat (<ul>, $level); //error when $level ==0 It should simply output an empty string silently I think. Btw, this function shuld add addtional parameters like this: string str_repeat (string input, int multiplier [, string conector]) "conector" should be anything to join the "intput", if an array was used as "input", when "mutiplier">0, ues input[0], else use input[1].