数组去重复

做一个新数组，重复的不加入

<script type="text/javascript">
 Array.prototype.delrepeat = function() {
    var arr = this;
    var _arr = new Array();
    for (var i in arr) {
        if (i == 'delrepeat') continue;
        if (_arr.length == 0) _arr.push(arr[i]);
        for (var j = 0; j < _arr.length; j++) {
            if (arr[i] == _arr[j]) {
                break;
            }
            if (j > _arr.length - 2) _arr.push(arr[i]);
        }
    }
    return _arr;
}
alert([1, 1, 7, ,9,1, 2, 2, 3, 4, 5,9, 5].delrepeat());
</script>