Common browsers way to judge

We do h5-compliant development or statistics commonly used when judging processing platform, the following are commonly used browser way to judge 
var UA = inBrowser && window.navigator.userAgent.toLowerCase (); 
var isIE = UA && / MSIE | Trident / .test (the UA); 
var isIE9 && UA.indexOf the UA = ( 'MSIE 9.0')> 0; 
var IsEdge && UA.indexOf the UA = ( 'Edge /')> 0; 
var isAndroid = (the UA UA.indexOf && ( 'Android')> 0); 
var isIOS = (&& /iphone|ipad|ipod|ios/.test(UA the UA));