Question

In which lifecycle method do you make requests for data in a class component?

A. ComponentDidMount
B. ComponentWillUnmount
C. ComponentWillUpdate
D. ComponentDidUpdate

Answer 1

The correct lifecycle method for making data requests in React class components is ComponentDidMount, which is called after the component mounts to the DOM. Other lifecycle methods like ComponentWillUnmount and ComponentDidUpdate serve different purposes, such as cleanup and updates, respectively.

Step-by-step explanation:

In class components of React, a common lifecycle method for making requests for data is ComponentDidMount. This method is called immediately after a component is mounted to the DOM, meaning that it is generally the best place to perform network requests or initial data fetching. The other lifecycle methods listed serve different purposes:

• ComponentWillUnmount is used for cleanup before the component is removed from the DOM, such as cancelling network requests or removing event listeners.
• ComponentWillUpdate has been deprecated in the latest versions of React, and was previously used before the component renders as a result of state or props changes.
• ComponentDidUpdate is used after the component updates and re-renders, which may be suitable for additional network requests in response to prop or state changes.

However, for the initial data fetching purpose, ComponentDidMount is the correct answer.