JavaScript 根据key获取url中value

代码参考于网上面试题

function getValue (key) {
	var _href = window.location.href;
	if(_href.split('?')[0] === _href) {
		return "";
	}
	var arr = _href.split('?')[1].split('&');
	var obj = {}
	for (var i=0; i<arr.length; i++) {
		_data = arr[i].split('=');
		obj[_data[0]] = _data[1];
	}
	return obj['key'];
}