# List of Destructive and Non-Destructive JavaScript Array Methods

> A list of destructive and non-destructive JavaScript array methods for those of us who can't always remember.

Source: https://curiouslychase.com/engineering/list-of-destructive-and-non-destructive-javascript-array-methods/

I can never remember which JavaScript Array methods are destructive and which are non-destructive.

A **destructive method** modifies the original array that the method is being run on. An example of this is `pop`:

```javascript
const instruments = ["Guitar", "Drums", "Keyboard"];
instruments.pop();
// instruments = ["Guitar", "Drums"]
```

A **non-destructive method** does not modify the original array and instead returns a shallow copy of the original value. An example of this is map:

```javascript

const instruments = ["Guitar", "Drums", "Keyboard"];
instruments.map(instrument => `${instrument} toot`);
// instruments = ["Guitar", "Drums", "Keyboard"]
```

# Destructive Methods
- [`copyWithin`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/copyWithin)
- [`fill`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/fill)
- [`pop`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/pop)
- [`push`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/push)
- [`reverse`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reverse)
- [`shift`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/shift)
- [`sort`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort)
- [`splice`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice)
- [`unshift`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/unshift)

# Non-Destructive Methods
- [`concat`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/concat)
- [`entries`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/entries)
- [`every`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/every)
- [`filter`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter)
- [`find`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find)
- [`findIndex`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findIndex)
- [`findLast`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findLast)
- [`findLastIndex`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findLastIndex)
- [`flat`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flat)
- [`flatMap`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flatMap)
- [`forEach`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach)
- [`Array.from()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/from)
- [`includes`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes)
- [`indexOf`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf)
- [`join`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/join)
- [`keys`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/keys)
- [`lastIndexOf`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/lastIndexOf)
- [`map`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map)
- [`reduce`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce)
- [`reduceRight`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduceRight)
- [`slice`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice)
- [`some`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/some)
- [`toLocaleString`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/toLocaleString)
- [`values`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/values)