I am using spread operator in an array like below:
const addOne = false;
const arr = [1, 2, 3]
const arr1 = [...arr, ...(addOne && [8, 9])];
console.log(arr1)And I got the error
TypeError: (addOne && [8,9]) is not iterable
at <anonymous>:4:32
While if I use spread operator in an object like:
const addOne = false;
const obj = {
name: 'peter',
age: 23
}
const obj1 = {
...obj,
...(addOne && obj)
}
console.log(obj1)it prints out the correct output
Anyone knows why?
(false && obj) evaluates to a boolean so its' not iterable.
When using the spread operator when building your obj1 object, js uses a different method to extract the key value pairs from an object (remember that a bool value in js is still an object), so it won't throw an error since it's expecting an object as an input.