js 浏览器判断

获取浏览器类型

function getBrowser() {
        var userAgent = navigator.userAgent //取得浏览器的userAgent字符串
        var isOpera = userAgent.indexOf('Opera') > -1 //判断是否Opera浏览器
        var isIE = userAgent.indexOf('compatible') > -1 && userAgent.indexOf('MSIE') > -1 && !isOpera //判断是否IE浏览器
        var isFF = userAgent.indexOf('Firefox') > -1 //判断是否Firefox浏览器
        var isSafari = userAgent.indexOf('Safari') > -1 //判断是否Safari浏览器
    var isChrome = navigator.userAgent.match(/chrome\/[\d.]+/gi) // 是否chrome
        if (isIE) {
          // var IE5 = IE55 = IE6 = IE7 = IE8 = false, IE9=false
          var reIE = new RegExp('MSIE (\\d+\\.\\d+);')
          reIE.test(userAgent)
          var fIEVersion = parseFloat(RegExp['$1']),
            IE55 = fIEVersion == 5.5,
            IE6 = fIEVersion == 6.0,
            IE7 = fIEVersion == 7.0,
            IE8 = fIEVersion == 8.0,
            IE9 = fIEVersion == 9.0

          if (IE55) {
            return 'IE55'
          }
          if (IE6) {
            return 'IE6'
          }
          if (IE7) {
            return 'IE7'
          }
          if (IE8) {
            return 'IE8'
          }
          if (IE9) {
            return 'IE9'
          }
        }//isIE end
        if (isFF) {
          return 'FF'
        }
        if (isOpera) {
          return 'Opera'
        }
        if(isSafari) {
           return 'Safari'     
        }
        if(isChrome) {
           return 'Chrome'     
        }
      }    

// 判断谷歌31版本及以下版本为低版本

var chrome = navigator.userAgent.match(/chrome\/[\d.]+/gi)
var isLowerVersionChrome = chrome && chrome[0].match(/[0-9]+/)[0] < 32