数组去重

    <script>
        function hasContain(arr,num) {
            for(var i=0;i<arr.length;i++){
                if(arr[i]==num){
                    return true;
                }
            }
            return false;
        }

        var arr=[1,2,3,4,5,2,3,8,4];
        var newArr=[];

        for(var i=0;i<arr.length;i++){
            if(!hasContain(newArr,arr[i])){
                newArr.push(arr[i])
            }
        }
        alert(newArr);  //1,2,3,4,5,8
    </script>