How to get the last digit of a number in JavaScript

In this tutorial, we will learn two different ways to get the last digit of a number in JavaScript.

In JavaScript, strings are the sequence of characters, where the index of the first character is 0, the second character is 1, third character is 3 and last character index is string.length-1 etc.

Get the last digit of a number

To get the last digit of a number, first we need to convert the number to a string and call the slice() method on a string by passing the -1 as an argument. Then convert the string back to a number.

Where negative index -1 is the last character index, same as string.length-1.

Here is an example:

const id = 2345;

const lastDigit = String(id).slice(-1);
console.log(Number(lastDigit));

Output:

5

In the example above, the String() and Number() functions are used to convert the string to a number or vice versa.

Alternatively, we can use the substring() method in JavaScript, to access the last digit of a number in JavaScript.

Here is an example:

const id = 2345;
// conveting the number to string
const strId = String(id);

const lastDigit = strId.substring(strId.length-1);
console.log(Number(lastDigit));

Output:

5