Memory leaks in JavaScript can be a common problem that can cause your application to slow down or even crash. In this blog post, I will discuss some of the best practices for avoiding memory leaks in JavaScript. I will cover topics such as how to identify memory leaks, how to prevent them from happening in the first place, and how to fix them when they do occur.
01. Use global scope wisely
As much as possible, don’t use the global scope. Make the best use of the local scope inside the functions, as that will be garbage collected and will keep memory free.
Try to define only constants, cache, and reusable variables in global. Do not use global space as a medium to pass values from one function to other, use function parameters instead.
02. Use the built-in garbage collector
To free up memory, you should use the built-in garbage collector.
03. Use manual memory management
To avoid circular references, You can use a technique called “manual memory management” by using JavaScript’s delete keyword to remove the properties that are creating the circular reference.
04. Use the let and const keywords
Use let and const keywords instead of var to declare variables. let and const are block-scoped, which means they are only available within the block they are defined in.
05. Remove event listeners
When you add an event listener to an element, it creates a reference to that element in memory. If you don’t remove the event listener when you’re done with it, it can cause a memory leak.
06. Use setTimeout and setInterval carefully
setTimeout and setInterval can cause memory leaks if you're not careful. Make sure to clear the timeout or interval when you're done with it.
07. Avoid circular references
Circular references occur when two or more objects reference each other. To avoid circular references, make sure to remove references to objects when you’re done with them.
08. Use the delete keyword
Use the delete keyword to remove properties from objects when you're done with them.
09. Use the WeakMap and WeakSet objects
Use the WeakMap and WeakSet objects to store weak references to objects. Weak references are not counted by the garbage collector, so they won't prevent an object from being garbage collected.
10. Use heap snapshots and profilers
You can use heap snapshots and profilers to identify memory leaks in your JavaScript code. Navigate to Chrome DevTools → Memory → Heap Snapshot → Take Snapshot. You can find detached DOM nodes by filtering Detached in the summary section.
11. Remove unused code
Remove unused code from your application to reduce the memory footprint.
