splice() / slice()
method
splice() modifies array in place (add/remove). slice() returns a shallow copy of a portion.
Syntax
array.splice(start, deleteCount, ...items) array.slice(start, end)
Example
javascript
// slice (non-destructive)
const a = [1, 2, 3, 4, 5];
console.log(a.slice(1, 3)); // [2, 3]
console.log(a.slice(-2)); // [4, 5]
// splice (destructive)
const b = ['a', 'b', 'c', 'd'];
const removed = b.splice(1, 2); // remove 2 at index 1
console.log(removed); // ['b', 'c']
console.log(b); // ['a', 'd']
b.splice(1, 0, 'x', 'y'); // insert at index 1
console.log(b); // ['a', 'x', 'y', 'd']