JavaScript Unshift 每个数组元素

Question

I have two arrays that contain objects. arr1 and arr2 . If I unshift arr1 to contain the elements of arr2 , the elements are not appended individually into arr1 , instead the whole array ( arr2 ) is appended at the beginning, for example:

arr1 = [{ele:1}, {ele:2}]
arr2 = [{ele:3}, {ele:4}]

I get: arr1 = [[{ele:3}, {ele:4}], {ele:1}, {ele:2}]

Notice the whole array inside instead of its objects.

I want: arr1 = [{ele:3}, {ele:4}, {ele:1}, {ele:2}]

My arrays are ko.observableArray(), maybe that makes a difference?

Answer 1

你去吧：

[].unshift.apply(arr1, arr2);

Answer 2

maybe this might be bit simpler

let arr1 = [{ ele: 1 }, { ele: 2 }];
let arr2 = [{ ele: 3 }, { ele: 4 }];
for (const iterator of arr2) {
  arr1.unshift(iterator);
}