JS 常用的判断或校验

1、判断是Android终端还是iOS终端
	let u = navigator.userAgent;
	let isAndroid = u.indexOf('Android') > -1 || u.indexOf('Adr') > -1;   //判断是否是 android终端
	let isIOS = !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/);     //判断是否是 iOS终端

	—— 封装成方法：
		/*判断客户端*/
		judgeClient() {
			let u = navigator.userAgent;
			let isAndroid = u.indexOf('Android') > -1 || u.indexOf('Adr') > -1;   //判断是否是 android终端
			let isIOS = !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/);     //判断是否是 iOS终端
			console.log('是否是Android：' + isAndroid); //true,false
			console.log('是否是iOS：' + isIOS);
			if(isAndroid){
				return 'Android';
			}else if(isIOS){
				return 'IOS';
			}else{
				return 'PC';
			}
		},

2、判断是Android还是iOS
	if (/(iPhone|iPad|iPod|iOS)/i.test(navigator.userAgent)) {
	  console.log('isIOS');
	} else if (/(Android)/i.test(navigator.userAgent)) {
	  console.log('isAndroid');
	} else {
	  console.log('isPC');
	}

	—— 封装成方法
		/*判断客户端*/
		judgeClient() {
			let client = '';
			if (/(iPhone|iPad|iPod|iOS)/i.test(navigator.userAgent)) {  //判断iPhone|iPad|iPod|iOS
				client = 'iOS';
			} else if (/(Android)/i.test(navigator.userAgent)) {  //判断Android
				client = 'Android';
			} else {
				client = 'PC';
			}
			sreturn client;
		},

3、判断PC还是移动端
	isPC() {
		/*true则pc，false则mobile*/
		let u = navigator.userAgent;
		let Agents = ["Android", "iPhone", "webOS", "BlackBerry", "SymbianOS", "Windows Phone", "iPad", "iPod"];
		let flag = true;
		for (let i = 0; i < Agents.length; i++) {
			if (u.indexOf(Agents[i]) > 0) {
				flag = false;
				break;
			}
		}
		return flag;
	}

4、判断多种访问终端
	//判断访问终端
	let browser = {
		versions: function () {
			let 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.*/), 									//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('Adr') > -1, 					//android终端
				iPhone: u.indexOf('iPhone') > -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
				weixin: u.indexOf('MicroMessenger') > -1, 										//是否微信
				qq: u.match(/\sQQ/i) == " qq" 													//是否QQ
			};
		}(),
		language: (navigator.browserLanguage || navigator.language).toLowerCase()
	};

5、判断浏览器当前使用的语言
	judgeLanguage() {
		// 判断浏览器当前使用的语言
		let currentLanguage = (navigator.browserLanguage || navigator.language).toLowerCase();    // 非IE
		if (!currentLanguage) {    // IE浏览器
			currentLanguage = navigator.browserLanguage;
		}
		console.log(currentLanguage);
		return currentLanguage;
	},