# How to get the last N characters of a string in JavaScript

By Atta Ur Rehman Shah (https://attacomsian.com/about). Published Oct 25, 2022. Topics: JavaScript.
Canonical URL: https://attacomsian.com/blog/javascript-get-last-n-characters-of-string

> Learn how to use the slice() and substring() methods to get the last N characters of a string in JavaScript.

You can use the `slice()` method to get the last N characters of a string in JavaScript, passing `-n` as a negative start index. For example, `str.slice(-2)` returns a new string containing the last 2 characters of the string.

```javascript
const str = 'JavaScript'

const last2 = str.slice(-2)
console.log(last2) // pt

const last4 = str.slice(-4)
console.log(last4) // ript

const last6 = str.slice(-6)
console.log(last6) // Script
```

The `slice()` method takes the start and end indexes as parameters and returns a new string containing a slice of the original string. It returns the extracted part as a new string and does not change the original string.

> When you pass only a start index, the `slice()` method returns the entire part of the string after the start index. 

When you pass a negative start index to `slice()`,  it counts backward from the last string character to find an equivalent index. So passing `-n` to `slice()` is equivalent to `str.length - n`, as shown below:

```javascript
const str = 'JavaScript'

const last4 = str.slice(-4)
console.log(last4) // ript

const last4Again = str.slice(str.length - 4)
console.log(last4Again) // ript
```

If you provide a start index greater than the string's length, the `slice()` method does not throw an error. Instead, it returns a copy of the original string:

```javascript
const str = 'JavaScript'

const last20 = str.slice(-20)
console.log(last20) // JavaScript
```

In the above example, we tried to get the last 20 characters of the string by passing `-20` as a negative start index, but the string `'JavaScript'` contains only 13 characters. Hence, `slice()` returns the entire string.

Alternatively, you could also use the `substring()` method to get the last N characters of a string in JavaScript:

```javascript
const str = 'JavaScript'

const last6 = str.substring(str.length - 6)
console.log(last6) // Script
```

The `substring()` method works similarly to `slice()` and returns a new string containing part of the original string specified using start and end indexes.

However, unlike `slice()`, the `substring()` method uses `0` as a start index if a negative number is passed as an argument:

```javascript
const str = 'JavaScript'

const last4 = str.substring(-4)
console.log(last4) // JavaScript
```