JS闭包取数组两个值的交际，为什么不对，大神帮看看

let arr1 = [1, 2, 2, 3];
let arr2 = [2, 2];

const mixedOfArr = function(arr1, arr2) {
    // 创建新数组
    let result = [];
    // 拷贝新数组待用
    let arr1New = arr1.slice();
    let arr2New = arr2.slice();
    return function() {
        let a1 = arr1New[0]; //每次取数组第一个
        let index = arr2New.indexOf(a1); //获取在第二个数组中的下标
        if (index > -1) {
            // 第二个数组中若存在
            result.push(a1);
            //删除第二个数组中存在的元素
            arr2New.splice(index, 1);
        }
        //删除第一个数组中遍历过的元素
        arr1New.splice(0, 1);
        if (arr1New.length == 0 || arr2New.length == 0) {
            arr1New = null;
            arr2New = null;
            //若其中一个数组遍历完，则返回数据
            return result;
        } else {
            // 否则递归
            mixedOfArr(arr1, arr2)
        }
    }
    return this;
}
let arrOf = new mixedOfArr(arr1, arr2);
let q = arrOf()
console.log(q);

你函数方法是不是用错了，arr1.slice();是需要带参数的啊

<script>
    llet arr1 = [1, 2, 2, 3];
    let arr2 = [2, 2];

    function compara(a, b) {
        let result = [];
        // 拷贝新数组待用
        let arr1New = a.slice();
        let arr2New = b.slice();
        arr1New.map(function(row,index){
            if(arr2New.indexOf(row) != -1){
                result.push(row);
            }
        })
        console.log(result);
    }
    compara(arr1, arr3);
    </script>