.forEach() Javascript 函数返回一个数组？

Question

Generally, It is said that 'forEach' doesn't return an array, whereas 'map' returns one. However, In my case, it is returning one. Below posted is my code. I am kind of confused. Any help would be appreciated.

//Code Snippet //
var arr = [1, 3, 2];
var arr_temp = [];

arr.forEach(function (i) {
  return arr_temp.push(i + i);
});

console.log(arr_temp);

I am getting the output as: [2,6,4]

Answer 1

It doesn't return anything. You can check that by logging the result of the forEach call:

 var arr = [1, 3, 2]; var arr_temp = []; console.log(arr.forEach(function (i) { return arr_temp.push(i + i); })); // undefined console.log(arr_temp); // 2, 6, 4