Simple Ways to Reverse String in JavaScript (No Need Loop)

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#javascript

Post's reading time 2 min read

JavaScript reverse string you probably heard it before. Especially during interview, I know you are looking for the answer or maybe you already get it but the way to solve that problem is not the one that could be most effective.

Yeah absolutely, I can deal to this problem with JavaScript for loop. But that’s not the only one and effective way.

In this article I’ll show you how to do it properly, I prefer using built-in Array function or method.

The Ways Reverse String in JavaScript

These are built-in function of an Array.

  • reverse()
  • reduce(callback)

Use Case

Before we get started, take a look to the following code below. I wanna make the value of variable me reversed (it’s my name).

javascript
let me = "Nurahmat";

With reverse() method

We first convert a value of variable me to an Array as we know that the default was string value.

try this on the browser console.

javascript
let me = "Nurahmat";
me.split('').reverse().join('');
// tamharuN

More simple, isn’t? Even, we don’t need to write more than one line of code.

With reduce() method

Another array built-in function, with reduce method we could also get the same result as well.

try this on the browser console.

javascript
let me = "Nurahmat";
me.split('').reduce(function(a,b) {
    return b + a;
})
// tamharuN

The flow is similar with the reverse() method, we should first convert string to Array, and see the additional callback of reduce() method.

Performance Testing

Now, let’s start do performance measurement between those methods, it’s a good idea if I include for loop to give you an answer Why you shouldn’t using for loop to reverse string in JavaScript?.

I created a simple code that wrap one goal, each method has different way to do it.

  • #method 1 Using for loop
  • #method 2 reverse() built-in method
  • #method 3 reduce() built-in method

It’s time for testing.

Perfomance Testing between those methods

As you can see above, the 2-3 method are more fast than the first method that use for loop. So, that’s all.

Conclusion

You can choose which one is the best fit for you, performance is quite important to consider.

Thanks, and see ya.