JavaScript Var 'Undefined' in Firefox; IE and Opera Work fine _cannot use 'in' operator to search for 'onproperty-优快云博客

本文探讨了JavaScript在不同浏览器中的兼容性问题，特别是针对Firefox、IE和Opera等浏览器的差异。文章提供了一种方法来统一处理innerText属性，确保代码能在多种浏览器中正确运行。

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I have some JavaScript that works fine in IE and Opera, but not Firefox.

The issue seems to be that Firefox is seeing the variable as undefined.

Do I have to declare that variable even though it should be inherited?

Your problem is that you're using document.all, and .innerText, neither of which are standard.

You should be using document.getElementById() to grab items, and .innerHTML to read their contents, if they're not form inputs.

If they are inputs, use .value instead of .innerText

Firfox支持：document.getElementById("c0").textContent

IE支持： document.getElementById("c0").innerText

<mce:script   language="javascript"   ><!--
function   isIE(){ 
//alert("")
//alert(window.navigator.userAgent)
//alert(window.navigator.userAgent.toString().toLowerCase().indexOf("msie"))
      if   (window.navigator.userAgent.toString().toLowerCase().indexOf("msie") >=1)
        return   true;
      else
        return   false;
}
//alert(isIE())

if(!isIE()){   //firefox   innerText   define
      HTMLElement.prototype.__defineGetter__(           "innerText",
        function(){
          var   anyString   =   "";
          var   childS   =   this.childNodes;
          for(var   i=0;   i <childS.length;   i++)   {
            if(childS[i].nodeType==1)
              anyString   +=   childS[i].tagName=="BR"   ?   '/n'   :   childS[i].innerText;
            else   if(childS[i].nodeType==3)
              anyString   +=   childS[i].nodeValue;
          }
          return   anyString;
        }
      );
      HTMLElement.prototype.__defineSetter__(           "innerText",
        function(sText){
          this.textContent=sText;
        }
      ); 
} 
alert(document.getElementById("aaaa").textContent)
alert(document.getElementById("aaaa").innerText)
// --></mce:script>