Sometimes, we want to convert ‘1’ to ‘0001’ in JavaScript.

In this article, we’ll look at how to convert ‘1’ to ‘0001’ in JavaScript.

How to convert ‘1’ to ‘0001’ in JavaScript?

To convert ‘1’ to ‘0001’ in JavaScript, we can use the string padStart method.

For instance, we write

const str = "1";
const ans = str.padStart(4, '0');

to call str.padStart with 4 and '0' to prepend '0'‘s to the str string into it reaches length 4.

Therefore, ans is '0001'.

Conclusion

To convert ‘1’ to ‘0001’ in JavaScript, we can use the string padStart method.