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为什么countMap1[t1]会true?什么情况下会false

<!DOCTYPE HTML>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=gb18030">
    <title>Untitled Document</title>
    
</head>
<body>
    <script type="text/javascript">   
        /*string boolean. number,underfined null function date window
         * param1 Array 
         * param2 Array
         * return true or false
         */
        function arraysSimilar(arr1, arr2){
        if(!(arr1 instanceof Array) || !(arr2 instanceof Array)){
            return false
        }
        if(arr1.length!==arr2.length){
            return false
        }
        var type=["string",'boolean','numbwe','undefined','null','function','date','window'];
        var i = 0,
        t1,t2,
        countMap1={},
        countMap2={};
        
        for (i;i<arr1.length;i++){
             t1=typeOf(arr1[i]);
             t2=typeOf(arr2[i]);
           if(countMap1[t1]){
               countMap1[t1]++;
           }  else{
               countMap1[t1]=1
           }
           if(countMap2[t2]){
               countMap2[t2]++;
           }  else{
               countMap2[t2]=1
           } 
        }
       


        function typeOf(ele){
            var r;
            if(ele===null) r="null";
            else if(ele===window) r='window';
            else if(ele instanceof Date) r='date';
            else if(ele instanceof Array) r='array';
            else r= typeof ele
            return r;
        }
       
        
        for(i=0;i<type.length;i++){
            if(countMap1[type[i]]!==countMap2[type[i]]){
                return false
            }
        }
        
        
        return true
        }
    </script>
    <script src="testData.js"></script>
</body>
</html>