Combine two arrays using the spread operator

const nums1 = [1, 2, 3];
const nums2 = [4, 5, 6];

// LONG FORM
let newArray = nums1.concat(nums2);

// SHORTHAND
newArray = [...nums1, ...nums2];

This syntax can also be used instead of pushing values to an array:

let numbers = [1, 2, 3];

// LONGER FORM
numbers.push(4);
numbers.push(5);

// SHORTHAND
numbers = [...numbers, 4, 5];

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