Memory leaks

A memory leak occurs when you program memory and forget to delete it once you are finished. The consequences of memory leak is that it reduces the performance of the computer by reducing the amount of available memory. Eventually, in the worst case, too much of the available memory may become allocated and all or part of the system or device stops working correctly, the application fails, or the system slows down vastly.

Stack memory
- Local variable storage: storing the variables local to a function’s scope and removing them once the function returns, avoiding memory leaks
useEffect
- The syntax of the useEffect hook also allows you to handle cleanup: something you want to do when the component unmounts (another example of how this hook recasts the traditional lifecycle methods) . In addition to running on unmount, the cleanup function will run before the effect runs again (i.e. when it runs in response to a change in one of the elements of the dependency araray). This is chiefly used to prevent memory leaks and the ‘update on unmounted component error’.
Heap memory
- Whereas stack memory with it’s LIFO structure has memory management built-in when programs allocate memory from the heap they must manually deallocate it when it is no longer required. This process of “freeing memory” is known as garbage collection. In a language like C, this is the explicit concern of the programmer and is not abstracted away. Failure to properly manage garbage collection is what causes Memory leaks.