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hooks

Lifecycle hooks are special functions in React that allow code to be executed at specific points in a component's lifecycle. Lifecycle hooks are called at different times depending on whether the component is mounted (inserted into the DOM), updated (with new properties or states), or unmounted (removed from the DOM).

There are several lifecycle hooks in React, each of which is called at a specific point in a component's lifecycle:

  • useEffect: this hook is called after each rendering of the component, that is to say when the component is mounted, updated or unmounted. This is a very useful hook for executing asynchronous code (for example, to make calls to an API) or for performing cleanup operations (for example, to remove event listeners).
  • useLayoutEffect: This hook is similar to useEffect, but it is executed synchronously after each component render. This is a useful hook for performing operations that need to be performed immediately after rendering, such as reading the dimensions of a DOM element.
  • useReducer: this hook allows you to manage the state of a component in a more advanced way than the useState hook, by using a reducer function to update the state of the component. This is a useful hook when the state of the component is complex or you want to use optimization methods like memoization.
  • useRef: this hook allows you to create an object Ref which can be used to store references to DOM elements or to store values ​​which must be preserved between different renderings of the component.
  • useMemo: this hook optimizes performance by storing the value of a function or a calculation which can be costly in resources. This makes it possible to not recalculate the stored value each time it is rendered, but only when the values ​​of the function's dependencies have changed.
  • useState: this hook allows you to manage the state of a component. It returns an array containing the current value of the state and a function to update this value.
  • useContext: this hook allows you to access the value of a React context from a component. It returns the context value for the current component and a function to update this value (if it is modifiable).
  • useImperativeHandle: this hook allows you to customize the object returned by a reference from a child component in a parent component. It is useful when you want to expose methods or properties from a child component to the parent component.
  • useDebugValue: this hook allows you to display a value in the React debugging tools to facilitate debugging a component. It is useful when you want to display an intermediate value in a component to see how it evolves over time.