Mastering Merge Sort: A Guide to Sorting Arrays in JavaScript

Tram Ho

Data sorting is a fundamental concept in computer science, and learning how to sort arrays is an important step in improving your own coding skills. One of the most popular sorting algorithms is called ‘merge sort’, and in this article we’ll take a little deeper look at how it works and how to use it in your own JavaScript projects.

What is mergesort

Mergesort is an algorithm that splits an array of elements into smaller subarrays. Those subarrays are sorted individually, and finally the subarrays are put back into a sorted array.

The reason this algorithm is called “mergesort” is because it uses a process called “merging” to combine smaller subarrays into a single sorted array. This process is repeated recursively, decomposing the array into smaller pieces, each containing only one element.

The main advantage of using mergesort is that it guarantees to sort n elements in `O(n * log n)` time, compared to other sorts like bubble sort and insertion sort. It is more efficient than algorithms.

How to use mergesort in JavaScript

Now that we understand the basic idea of ​​mergesort, let’s see how to implement it in JavaScript. Here’s an example of a basic implementation.

In this example we have two functions: `mergeSort` and `merge` . `mergeSort` function takes an array as input and uses recursion to break it down into smaller subarrays. The `merge` function takes two sorted subarrays and puts them back into a single sorted array.

Example of use

Now that we’ve learned how to implement mergesort in JavaScript, let’s look at a real-world example of using it.

1. Sort the list of names

If you have a list of names that need to be sorted alphabetically, you can do it quickly and efficiently using mergesort. For example.

2. Sort the list of numbers

When dealing with lists of numbers that need to be sorted in ascending or descending order, it can be achieved by using merge sort. Here is an example of how to sort a list of numbers in ascending order.

3. Sort the list of objects

Merge sort can also be used to sort a list of objects based on certain properties. Here is an example of how to sort a list of objects with information about people by last name.

4. Sort a list of custom data structures

Besides simple data types like strings and numbers, mergesort can also be used to sort custom data structures like linked lists and binary trees. Here is an example of how to sort a linked list.

5. Sort large amounts of data

The guaranteed time complexity of mergesort is `O(n * log n)` , making it suitable for sorting large amounts of data. It is therefore suitable for use in big data and data science applications.

Conclusion

Mergesort is a powerful and efficient sorting algorithm that can be used to sort a wide range of data types, from arrays of numbers and strings to complex data structures like linked lists and binary trees. A major advantage of mergesort is its guaranteed time complexity of `O(n * log n)` , making it suitable for sorting large amounts of data. With this guide and examples, you’ll have the knowledge to implement mergesort in your own `JavaScript` projects and improve your own coding skills.

As always, I hope you enjoyed this article and learned something new.

Thank you very much. See you in the next article!