js判断ios、android

<script type="text/javascript">
	var browser={
		versions:function(){
		var u = navigator.userAgent, app = navigator.appVersion;
		return {
		trident: u.indexOf('Trident') > -1,  //IE内核
		presto: u.indexOf('Presto') > -1,  //opera内核
		webKit: u.indexOf('AppleWebKit') > -1,  //苹果、谷歌内核
		gecko: u.indexOf('Gecko') > -1 && u.indexOf('KHTML') == -1,  //火狐内核
		mobile: !!u.match(/AppleWebKit.*Mobile.*/)||!!u.match(/AppleWebKit/),  //是否为移动终端
		ios: !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/),  //ios终端
		android: u.indexOf('Android') > -1 || u.indexOf('Linux') > -1,  //android终端或者uc浏览器
		iPhone: u.indexOf('iPhone') > -1 || u.indexOf('Mac') > -1,  //是否为iPhone或者QQHD浏览器
		iPad: u.indexOf('iPad') > -1,  //是否iPad
		webApp: u.indexOf('Safari') == -1  //是否web应该程序，没有头部与底部
		};
		}()
	}
	function downhref(){
		if(browser.versions.ios || browser.versions.iPhone || browser.versions.iPad){
			window.location = "wapdown.action?type=ios";
		}else{
			window.location = "wapdown.action?type=android";
		}
	}
</script>