Get the last N elements from an Array in JavaScript

Get the last N elements from an Array #

To get the last N elements from an array, call the slice method on the array, passing in -n as a parameter, e.g. arr.slice(-3) returns a new array containing the last 3 elements from the original array.

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const arr = ['a', 'b', 'c', 'd', 'e'];

const last3 = arr.slice(-3); // 👉️ ['c', 'd', 'e']
console.log(last3);

const last2 = arr.slice(-2); // 👉️ ['d', 'e']
console.log(last2);

The parameter we passed to the Array.slice method is the start index.

This is the same as passing array.length - 3 as an argument to the slice method.

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const arr = ['a', 'b', 'c', 'd', 'e'];

const last3 = arr.slice(-3);
console.log(last3); // 👉️ ['c', 'd', 'e']

const last3Again = arr.slice(arr.length - 3);
console.log(last3Again); // 👉️ ['c', 'd', 'e']

Either way, we tell the slice method, copy the last 3 elements of the array and place them in a new array.

Even if we try to get more elements than the array contains, Array.slice won't throw an error, instead it returns a new array with all elements.

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const arr = ['a', 'b', 'c'];

const last100 = arr.slice(-100);
console.log(last100); // 👉️ ['a', 'b', 'c']

In the example we tried to get the last 100 elements of an array, which only contains 3 elements.

In this case all elements get copied to the new array.