# Get the Last Digit of a Number in JavaScript

Sat Oct 23 20211 min read

Photo by Rob Wilson

## Get the Last Digit of a Number#

To get the last digit of a number:

1. Convert the number to a string and call the `slice()` method on the string, passing it `-1` as a parameter.
2. The `slice` method will return the last character in the string.
3. Convert the string back to a number to get the last digit.
index.js
```Copied!```// ๐๏ธ Decimal numbers
const num1 = 1357.579;
const lastDigit1Str = String(num1).slice(-1); // ๐๏ธ '9'
const lastDigit1Num = Number(lastDigit1Str); // 9

// ๐๏ธ Integers
const num2 = 1357;
const lastDigit2Str = String(num2).slice(-1); // ๐๏ธ '7'
const lastDigit2Num = Number(lastDigit2Str); // ๐๏ธ 7
``````

This approach works for integer and float numbers.

The first step is to use the `String` object to convert the number to a string, so we can call the String.slice method on it.

Indexes are zero-based in JavaScript. The index of the first character in a string is `0` and the last - `str.length - 1`.

The only parameter we passed to the `slice` method is the start index - the index at which to start extraction.

Passing a negative index of `-1`, means give me the last character of the string.

This is the same as passing `string.length - 1` as the start index.

index.js
```Copied!```const str = 'Hello World';

const last1 = str.slice(-1); // ๐๏ธ d
console.log(last1);

const last1Again = str.slice(str.length - 1); // ๐๏ธ d
console.log(last1Again);
``````

The `slice` method returns a string, so the last step is to convert it back to a number, using the `Number` object.