如何吧一维数组变成多维数组 用原生js

如何吧一维数组变成多维数组 用原生js

var arr=[1,2,3,4,5,6,7,8,9,0]

变成多维或者二维数组

 function fn(arr, num) {
            let newArr = []
            const total = Math.ceil(arr.length / num)
            console.log(total);
            for (let i = 0; i < total; i++) {
                a = arr.slice(i * num, (i + 1) * num)
                newArr.push(a)
            }
            return newArr
        }
        let arr = [1,2,3,4,5,6,7,8,9,0]
        console.log(fn(arr, 4));