php的json_encode不兼容JSON_UNESCAPED_UNICODE

//php的json_encode不兼容JSON_UNESCAPED_UNICODE的解决方案
function _json_encode($value) {
	if (version_compare(PHP_VERSION, '5.4.0', '<')) {
		$str = json_encode($value);
		$str = preg_replace_callback(
				"#\\\u([0-9a-f]{4})#i", function($matchs) {
			return iconv('UCS-2BE', 'UTF-8', pack('H4', $matchs[1]));
		}, $str
		);
		return $str;
	} else {
		return json_encode($value, JSON_UNESCAPED_UNICODE);
	}
}

　　

;