Componentdidmount equivalent on a React function/Hooks component?

Nitty-gritty of useEffect and managing dependencies

useEffect is truly multifaceted, expertly mimicking different lifecycle events. The dependency array is its secret sauce:

• An empty array works like componentDidMount, only running the effect upon the component's mount.
• Including variables inside the array emulates componentDidUpdate, running the effect when the specified variables change.
• A return function inside useEffect acts like componentWillUnmount, running during the component's unmount phase.

Code on updates:

useEffect(() => {
  // Runs on mount and whenever `stateVar` changes because who doesn't love a good change?
}, [stateVar]);
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Clean-up function:

useEffect(() => {
  // Sets up the stage
  return () => {
    // The after-party clean-up crew
  };
}, [propsVar]);
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Efficient use of useEffect with dependencies

When handing dependencies, it's crucial to strike a balance to allow efficient re-rendering. It's all about triggering updates only with relevant state or prop changes, keeping things quick and snappy, and restraining from creating a render monster.

Juggling state changes and effects: Mastery over useState and useEffect can make state changes operate with lifecycle-like precision. Keep in mind that any call to setState within useEffect beckons a re-render, so measure twice and cut once!

Beware of warning landmines: Dodging complex states within useEffect can save you from the headache of confusing warnings. Never fear complexity but do fear complicity with complexity! Aim for simpler states, or split the effect into bite-sized, manageable parts with separate useEffect calls.

Pro tips and advanced usage patterns

useEffect usually fits snugly for all cases, provided the right custom hooks like use-did-mount are used for a cleaner mounting logic.

n useEffect s for n dependencies: More useEffect calls combined with varied dependency arrays can smartly capture specific update cycles. Balance is the key.

useCallback for an optimization power-up: If down the line you pass callback functions to child components wrapped in useCallback, needless renders can take a back seat improving performance.

Class over function: Big picture thinking involves evaluating if Object-Oriented Programming (OOP) trumps Plain Old JavaScript (POP) in your use case. Occasionally, avoiding useEffect pitfalls and opting for class components can save the day as your application scales up.