JS determines whether it is IE browser and IE version

<script type="text/javascript"> if (IEVersion() == -1) { window.alert("不是ie浏览器") } else { window.alert("是IE" + IEVersion()) } function IEVersion() { var userAgent = navigator.userAgent; //取得浏览器的userAgent字符串 var isIE = userAgent.indexOf("compatible") > -1 && userAgent.indexOf("MSIE") > -1; //判断是否IE<11浏览器 var isEdge = userAgent.indexOf("Edge") > -1 && !isIE; //判断是否IE的Edge浏览器 var isIE11 = userAgent.indexOf('Trident') > -1 && userAgent.indexOf("rv:11.0") > -1; if (isIE) { var reIE = new RegExp("MSIE (\\d+\\.\\d+);"); reIE.test(userAgent); var fIEVersion = parseFloat(RegExp["$1"]); if (fIEVersion == 7) { return 7; } else if (fIEVersion == 8) { return 8; } else if (fIEVersion == 9) { return 9;} else if (fIEVersion == 10) { return 10; } else { return 6;//IE版本<=7 } } else if (isEdge) { return 'edge';//edge } else if (isIE11) { return 11; //IE11 } else { return -1;//不是ie浏览器 } } </script>