Mohamed Ibrahim

How to reverse a string in JavaScript

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Mohamed Ibrahim
·

2 min read

In this article we will learn how to reverse a string.

Unfortunately, there is no built-in function in JavaScript that directly reverses a string, and this is where your role as a programmer comes in.

And if you are familiar with the basics of JavaScript, you will do so easily.

Problem

Well, now we have a problem, which is that we want to reverse the string.

This is our string:

Hello world

And we want to reverse it so that it becomes like this:

dlrow olleH

And we said that there's no built-in function that does this, so how will you solve this problem?

Think a little and then come back to the solution.

Solution:

Well, the solution is simple, there is not really a function that reverse the string, but there is a function that reverse the array, right?

Now the solution is to convert the string into an array, then reverse it, and then return it again as a string.

Summarize the solution as follows:

  • Convert string into an array
  • Reverse the string
  • Convert back the array to a string

I know, I know, it might be a little difficult for you, especially if you are a beginner.

But after writing the code things will start to make sense.

// Our string
const myString = "Hello world";

// Convert string to an array
const toArray = myString.split("");

// Reverse array
const reversedArray = toArray.reverse();

// Return it back to string
const result = reversedArray.join("");

// Print result
console.log(result);

Output

dlrow olleH

Ok, do you understand the previous code? We consider the answer is no.

Explanation of the solution:

First of all, we convert the string into an array with the split function.

// Convert string to an array
const toArray = myString.split("");
console.log(toArray);

Output

[
  'H', 'e', 'l', 'l',
  'o', ' ', 'w', 'o',
  'r', 'l', 'd'
]

Well now that the string is an array, what next?

There is a built-in function that reverse the array, right? We will use it.

// Reverse array
const reversedArray = toArray.reverse();
console.log(reversedArray);

Output

[
  'd', 'l', 'r', 'o',
  'w', ' ', 'o', 'l',
  'l', 'e', 'H'
]

Now we will return that array to a string using join method

// Return it back to string
const result = reversedArray.join("");
console.log(result);

Output

dlrow olleH

Yay! 🚀 And here the solution is complete, if you have another solution let me know :)

Thank you for reading

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