public function ltrim($str, $charlist = null)
    {
        return isset($charlist) ? ltrim($str, $charlist) : ltrim($str);
    }
public function ltrim($str, $charlist = null)
    {
        return isset($charlist) ? ltrim($str, $charlist) : ltrim($str);
    }
public function ltrim ( $ str , $ charlist = null ) { return isset ( $ charlist ) ? ltrim ( $ str , $ charlist ) : ltrim ( $ str ) ; }
left trim string

@param string $str
@param array $charlist
@return string
left trim string