判断当前浏览器

function getExplorer(){
        var browser;
        var explorer = window.navigator.userAgent ;
        var a1 = navigator.userAgent;
        var yesIE = a1.search(/Trident/i);//判断IE 
        var IE = a1.search(/rv:11.0/i);//判断IE 11
        if(IE>0){
            return browser = 'ie11';    
        }else
        //ie 
        if (yesIE > 0) {
            return browser = 'ie';
        }
        //Edge
        else if(explorer.indexOf("Edge") >= 0){
            return browser = 'Edge';
        }
        //firefox 
        else if (explorer.indexOf("Firefox") >= 0) {
            return browser = 'Firefox';
        }
        //Chrome
        else if(explorer.indexOf("Chrome") >= 0){
            return browser = 'Chrome';
        }
        //Opera
        else if(explorer.indexOf("Opera") >= 0){
            return browser = 'Opera';
        }
        //Safari
        else if(explorer.indexOf("Safari") >= 0){
            return browser = 'Safari';
        }
    }