php 常用方法

//返回json数据给js
function json_output($err_code = 0 , $error_message = '' , $data = [] ,  $redirect = '',$jsonp = FALSE){
	$ret = array(
		'error_code'    => $err_code,
		'error_message' => $error_message,
		'data'          => is_array($data)?$data:(array)$data,
		'redirect'      => $redirect,
	);
	header("Content-Type:application/json;charset=utf-8");
	$output = json_encode($ret);
	if($jsonp){
		$callback_func = isset($_GET['callback'])?$_GET['callback']:md5(time());
		$output = $callback_func.'('.$output.')';
	}
	echo $output;exit;
}
/**
 * 计算中文字符串长度
 */
function utf8_strlen($string = null)
{
	// 将字符串分解为单元
	preg_match_all ( '/./us', $string, $match );
	// 返回单元个数
	return count ( $match [0] );
}