JS判断浏览器是否支持webp

function BrowserType() 

{ 

   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 isIE=window.ActiveXObject || "ActiveXObject" in window

   // var isEdge = userAgent.indexOf("Windows NT 6.1; Trident/7.0;") > -1 && !isIE; //判断是否IE的Edge浏览器 

   var isEdge = userAgent.indexOf("Edge") > -1; //判断是否IE的Edge浏览器

   var isFF = userAgent.indexOf("Firefox") > -1; //判断是否Firefox浏览器 

   var isSafari = userAgent.indexOf("Safari") > -1 && userAgent.indexOf("Chrome") == -1; //判断是否Safari浏览器 

   var isChrome = userAgent.indexOf("Chrome") > -1 && userAgent.indexOf("Safari") > -1&&!isEdge; //判断Chrome浏览器 

   if (isIE)  

   { 

    /*

      var reIE = new RegExp("MSIE (d+.d+);"); 

      reIE.test(userAgent); 

      var fIEVersion = parseFloat(RegExp["$1"]); 

      if(userAgent.indexOf('MSIE 6.0')!=-1){

          return "IE6";

      }else if(fIEVersion == 7) 

          { return "IE7";} 

      else if(fIEVersion == 8) 

          { return "IE8";} 

      else if(fIEVersion == 9) 

          { return "IE9";} 

      else if(fIEVersion == 10) 

          { return "IE10";} 

      else if(userAgent.toLowerCase().match(/rv:([d.]+)) like gecko/)){ 

              return "IE11";

          } 

      else

        { return "0"}//IE版本过低

      */

      return "IE";

    }//isIE end 

    if (isFF) { return "FF";} 

    if (isOpera) { return "Opera";} 

    if (isSafari) { return "Safari";} 

    if (isChrome) { return "Chrome";} 

    if (isEdge) { return "Edge";} 

}//myBrowser() end

// 判断是否支持webp

  var webp = new Image();

  webp.src = 'data:image/webp;base64,UklGRjIAAABXRUJQVlA4ICYAAACyAgCdASoBAAEALmk0mk0iIiIiIgBoSygABc6zbAAA/v56QAAAAA==';

  webp.onerror = function(){

      supportWebp = false;

      var slider = $(".swiper-wrapper").html();

      slider = slider.replace(/-wx.webp/g,'-web.jpg');

      console.log(slider);

      $(".swiper-wrapper").html(slider);

  };

  webp.onload = function(){

      supportWebp = true;

  };