Summary and Key Takeaways

• Actions that are not directly related to the main process of a function can be considered side effects.
• Side effects can be asynchronous tasks (for example, sending an HTTP request), but can also be synchronous (for example, console.log() or accessing browser storage).
• Side effects are often needed to achieve a certain goal, but it's a good idea to separate them from the main process of a function.
• Side effects can become problematic if they cause infinite loops (because of the update cycles between effect and state).
• useEffect() is a React Hook that should be used to wrap side effects and perform them in a safe way.
• useEffect() takes an effect function and an array of effect dependencies.
• The effect function is executed directly after the component function was invoked (not simultaneously).
• Any value, variable, or function used inside of an effect should be added to the dependencies array.
• Dependency array exceptions...