JavaScript String Manipulation: How to Use Split, Reverse, and Join

Introduction

In this article, we will look at three JavaScript methods: split(), reverse(), and join(). These methods are helpful for working with strings and carrying out tasks such as reversing text or changing the order of words.

Prerequisites

No prior experience is needed—just a willingness to dive into JavaScript and experiment with these methods.

The split() Method

The split() method breaks a string into an array based on a specified delimiter, which is passed as an argument. The delimiter tells the program where to "cut" the string. For example, if you have a sentence like "This is a lovely sandwich" and you want to break it into individual words, you can use a space (' ') as the delimiter.

const string = "This is a lovely sandwich";
const splitString = string.split(" ");

When you provide a space (' ') as the argument, the code looks for that space in the string and "splits" the string at each occurrence. This creates an array, where each word becomes an individual element.

The result of the above code is:

Array(5) [ "This", "is", "a", "lovely", "sandwich" ]

Pretty neat, right?

You can use any delimiter you want. For instance, if you have a hyphenated string like "hi-there-how-are-you-doing!" and you want to split it by hyphens, just use '-' as the delimiter:

const hyphen = "hi-there-how-are-you-doing!";
const splitHyphen = hyphen.split("-");

This results in:

Array(6) [ "hi", "there", "how", "are", "you", "doing!" ]

This method opens up many possibilities for manipulating strings. But now, you might be thinking: Okay, that’s great, but I started with a string and now I have an array. How do I get my string back?

Let’s move on to the next method.

The join() Method

The join() method can be used on an array to turn it back into a string. Just like split(), the join() method takes an argument that specifies how to join the array elements. The difference is that instead of breaking a string, join() uses the argument to combine the array elements back into a single string.

For example, using the splitHyphen array from earlier, you can join it back into a string by providing a space as the argument:

const joinedString = splitHyphen.join(" ");

This results in:

"hi there how are you doing!"

It’s like magic! Now your array is transformed back into a string, with spaces between each word.

The reverse() Method

The reverse() method changes the order of elements in an array to be the opposite of what it was. This method is called directly on the array, without any arguments, and it simply reverses the order of the elements.

For example, if you want to reverse the elements in the splitHyphen array, you can do this:

const reversedArray = splitHyphen.reverse();

The result is:

[ "doing!", "you", "are", "how", "there", "hi" ]

You can even use join() again to turn this reversed array back into a string:

const reversedString = reversedArray.join(" ");

This gives you:

"doing! you are how there hi"

Pretty cool, right?

Conclusion

In this article, we explored three essential methods in JavaScript: split(), reverse(), and join(). We looked at how they work together to manipulate strings and arrays, transforming them in flexible ways. I hope this helps you in your JavaScript journey and inspires you to experiment further!

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Thank you for reading! If you have any questions or want to share your thoughts on JavaScript string manipulation, feel free to reach out to me on Twitter @km_fsdev.