6.6 Deleting Elements in an Array

We've already seen how to add elements to an array. Removing follows a symmetrical pattern: there are three methods, one for the end, one for the beginning, and one for any position in the middle. Take this array:

const numbers = [1, 2, 3, 4];

pop, shift and splice

• numbers.pop() — removes the last element and returns it. After the call: [1, 2, 3] and the returned value is 4.
• numbers.shift() — removes the first element and returns it. After the call: [2, 3] and the returned value is 1.
• numbers.splice(index, count) — removes count elements starting at index, anywhere in the middle.

const last  = numbers.pop();       // 4 ; numbers is now [1, 2, 3]
const first = numbers.shift();     // 1 ; numbers is now [2, 3]

const arr = [1, 2, 3, 4];
arr.splice(2, 1);                  // remove 1 element at index 2 → [1, 2, 4]
arr.splice(0, 2);                  // remove 2 elements from index 0 → [4]

All three methods mutate the array in place. pop and shift also return the element they removed, which is handy when you want to keep a reference to it. splice can remove several elements at once by passing a count greater than 1.

To recap: pop for the end, shift for the beginning, splice for the middle. See you in the next video, where we'll see how to completely empty an array.