爲什麼有不同版本的IE則不會觸發

Question

我有以下腳本，檢查我的計算機運行的是什麼版本的IE瀏覽器，並使用樣式表，以及顯示警報語句：

var div = document.createElement("div"); 
     div.innerHTML = "<!--[if lte IE 9]><i></i><![endif]-->"; 
     var isIeLessThan9 = (div.getElementsByTagName("i").length == 1); 
     if (isIeLessThan9) { 
      alert("<=9"); 
      document.write('<link rel="stylesheet" href="theStyles/defaultStyle_ie.css" type="text/css" charset="utf-8" />'); 
      document.write('<link rel="stylesheet" href="theStyles/captionStyle_ie.css" type="text/css" charset="utf-8" />'); 
     } 
     if (!isIeLessThan9) { 
      alert(">9"); 
      document.write('<link rel="stylesheet" href="theStyles/defaultStyle.css" type="text/css" charset="utf-8" />'); 
      document.write('<link rel="stylesheet" href="theStyles/captionStyle.css" type="text/css" charset="utf-8" />'); 
     } 

發生了什麼事是IE版本10及更高版本顯示>=10和任何小於IE版本10仍顯示>=10

我該如何解決它？

編輯：

這是更新的代碼應該解決這個問題：

<script type="text/javascript"> 
    var isMobile = { 
     Android: function() { 
      return navigator.userAgent.match(/Android/i); 
     }, 
     BlackBerry: function() { 
      return navigator.userAgent.match(/BlackBerry/i); 
     }, 
     iOS: function() { 
      return navigator.userAgent.match(/iPhone|iPad|iPod/i); 
     }, 
     Opera: function() { 
      return navigator.userAgent.match(/Opera Mini/i); 
     }, 
     Windows: function() { 
      return navigator.userAgent.match(/IEMobile/i); 
     }, 
     any: function() { 
      return (isMobile.Android() || isMobile.BlackBerry() || isMobile.iOS() || isMobile.Opera() || isMobile.Windows()); 
     } 
    }; 



    navigator.sayswho= (function(){ 
    var ua= navigator.userAgent, tem, 
    M= ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*([\d\.]+)/i) || []; 
    if(/trident/i.test(M[1])){ 
     tem= /\brv[ :]+(\d+(\.\d+)?)/g.exec(ua) || []; 
     return 'IE '+(tem[1] || ''); 
    } 
    M= M[2]? [M[1], M[2]]:[navigator.appName, navigator.appVersion, '-?']; 
    if((tem= ua.match(/version\/([\.\d]+)/i))!= null) M[2]= tem[1]; 
    return M.join(' '); 
})(); 
var browserversion1 = navigator.sayswho.split(" "); 
var browserversion2 = browserversion1[1].split(".")[0].split(","); 
var isIeLessThan10 = browserversion1[0] == "IE" && browserversion2[0] < 10; 




    if (!isMobile.any()) { 
     if (isIeLessThan10) { 
      alert("IE<10"); 
      document.write('<link rel="stylesheet" href="theStyles/defaultStyle_ie.css" type="text/css" charset="utf-8" />'); 
      document.write('<link rel="stylesheet" href="theStyles/captionStyle_ie.css" type="text/css" charset="utf-8" />'); 
     } 
     else { 
      alert("IE>=10 || !IE"); 
      document.write('<link rel="stylesheet" href="theStyles/defaultStyle.css" type="text/css" charset="utf-8" />'); 
      document.write('<link rel="stylesheet" href="theStyles/captionStyle.css" type="text/css" charset="utf-8" />'); 
     } 
    } 
    else { 
     alert("mobile"); 
     document.write('<link rel="stylesheet" href="theStyles/defaultStyle_mobile.css" type="text/css" charset="utf-8" />'); 
     document.write('<link rel="stylesheet" href="theStyles/captionStyle_mobile.css" type="text/css" charset="utf-8" />'); 
    } 
</script> 

雙方IE8和FF顯示警報，IE>=10 || !IE

Answer 1

我寧願使用這個函數可以獲取瀏覽器及其版本，而不是依靠html標籤數量，這可以很容易地改變你的內容：JSFiddle

navigator.sayswho= (function(){ 
    var ua= navigator.userAgent, tem, 
    M= ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*([\d\.]+)/i) || []; 
    if(/trident/i.test(M[1])){ 
     tem= /\brv[ :]+(\d+(\.\d+)?)/g.exec(ua) || []; 
     return 'IE '+(tem[1] || ''); 
    } 
    M= M[2]? [M[1], M[2]]:[navigator.appName, navigator.appVersion, '-?']; 
    if((tem= ua.match(/version\/([\.\d]+)/i))!= null) M[2]= tem[1]; 
    return M.join(' '); 
})(); 
var browserversion1 = navigator.sayswho.split(" "); 
var browserversion2 = browserversion1[1].split(".")[0].split(","); 
var isIeLessThan10 = (browserversion1[0] == "IE" || browserversion1[0] == "MSIE") && browserversion2[0] < 10;