Remove last element from an array without using pop()

Question

I'm new to JavaScript. I want to remove last element from an array, without using pop method. I've tried using length property, but I'm getting undefined in my console. Please help!

function lastElement(array) {

   return array[array.length-1];

}

lastElement([3,4,5,6]);

score 8 · Answer 1 · answered Apr 17 '19 at 20:09

8

Use slice()

function lastElement(array) {
   return array.slice(0,array.length-1);
}

lastElement(array);

answered Apr 17 '19 at 20:09

Void Spirit

879
6
18

Thank you for helping! Slice is a better option – Jojo Apr 17 '19 at 20:11
`slice` does not change the array nor the length of the array. it does not remove an item. – Nina Scholz Apr 17 '19 at 20:14
@NinaScholz i know, but since it returns new array you can assign it. Thanks for your point. And I think author did not ask the question in right way – Void Spirit Apr 17 '19 at 20:18
1

an assignment inside of the function does not change the array of the call (outside), because ot loses the object reference. you may try it. – Nina Scholz Apr 17 '19 at 20:19
@NinaScholz I meant not in function. To be more clear `arr = lastElement(arr)` – Void Spirit Apr 17 '19 at 20:21
`lastElement` should return an element, not the array. – Nina Scholz Apr 17 '19 at 20:21
@NinaScholz But anyways I understand your point, if you go by the question my answer is incorrect – Void Spirit Apr 17 '19 at 20:22
And what else should one go by, if not the question? ... which makes this answer incorrect. – Asons Apr 17 '19 at 20:25

Nina Scholz · Answer 2 · 2019-04-17T20:11:24.673

You need to take the element first and then decrement the array length.

BTW, the handed over parameters are not an array. You need an array for this task, because if you take only arguments, the length change makes no sense.

function lastElement(array) {
    var temp = array[array.length - 1];
    array.length = Math.max(0, array.length - 1); // prevent assigning negative values
    return temp;
}

var array = [3, 4, 5, 6];

console.log(lastElement(array));
console.log(lastElement(array));
console.log(lastElement(array));
console.log(lastElement(array));
console.log(lastElement(array));
console.log(array);

Remove last element from an array without using pop()

2 Answers2