Some Reactjs advanced terms to know

What is an event loop

The event loop is the secret behind JavaScript’s asynchronous programming. JS executes all operations on a single thread, but using a few smart data structures, gives us the illusion of multi-threading. Let’s take a look at what happens on the back-end. The call stack is responsible for keeping track of all the operations in line to be executed. Whenever a function is finished, it is popped from the stack. The event queue is responsible for sending new functions to the track for processing. It follows the queue data structure to maintain the correct sequence in which all operations should be sent for execution.

React Hooks: useCallback and useMemo The main difference between the two is that ‘useCallback’ returns a memoized callback and ‘useMemo’ returns a memoized value that is the result of the function parameter. To recap: you should not use ‘useCallback’ and ‘useMemo’ for everything. ‘useMemo’ should be used for big data processing while ‘useCallback’ is a way to add more dependency to your code to avoid useless rendering.

Var, Let, and Const – What's the Difference?

const is a signal that the identifier won’t be reassigned. let is a signal that the variable may be reassigned, such as a counter in a loop, or a value swap in an algorithm. It also signals that the variable will be used only in the block it’s defined in, which is not always the entire containing function. var is now the weakest signal available when you define a variable in JavaScript. The variable may or may not be reassigned, and the variable may or may not be used for an entire function, or just for the purpose of a block or loop.