1. Can you please explain the purpose of the render() function?
This question requires you to go beyond an explanation of terminology and contextualise the render() function’s purpose.
Sample answer: “The render() method is critical since it is responsible for refreshing the UI. Each React component has a render() method that assists in returning a single React element for each element provided to the DOM.”
2. How do you distinguish between DOM and virtual DOM?
It is vital to recollect facts about the document object model to be able to answer this question appropriately.
Sample answer: “The Document Object Model (DOM) is a visual representation of the textual content presented by HTML code. The virtual DOM connects to the HTML DOM in that it comes from it. The virtual DOM is an abstraction of the HTML DOM. Since the DOM itself was already an abstraction, most people consider the virtual DOM as an abstraction of an abstraction.”
3. What are stateless components?
This question requires you to go beyond a definition of words and contextualise the render() function’s purpose.
Sample answer: “The render() method is critical because it is responsible for refreshing the UI. Each React component has a render() method that assists in returning a single React element for each element provided to the DOM.”
4. When is it appropriate to utilize refs in React?
Interviewers often ask this question to find out your level of expertise with certain parts of the React framework. Your response can identify references and explain their contextual significance.
Sample answer: “Within a framework, refs are the tools that store existing components and generate related items. They are helpful when an additional method has to be introduced to a component. This is due to the fact that their storage role enables developers to do DOM measurements.”
5. Define JSX.
6. What is a controlled component? How does it compare to the definition of an uncontrolled component?
The interviewer may ask this question to know if you have a working knowledge of the various components used in React. Your response can identify both controlled and uncontrolled components while also explaining the difference between the two.
Sample answer: “A controlled component is a component you can implement forms in with quite easily, but an uncontrolled component is a substitute for a controlled component, one in which the DOM maintains data forms. Another approach to characterize these two concepts is that controlled components do not keep their own internal state and are thus easily manipulable, whereas uncontrolled components do.”
7. What differentiates React from other ways developers build applications?
Sample answer: “React, as a JS framework, is distinct from previous approaches to user interface development in that developers operate within a pre-existing component library. The library feature of JS frameworks eliminates the need for time-consuming coding. React is distinct from other JS frameworks in that it is not opinionated. For example, due to the nature of its runtime scripting, Angular is a highly opinionated JS framework. This has its advantages but can also be restrictive. React is more adaptable and has little or no preference for user interface architecture, which allows for greater flexibility, innovation and originality.”