What is the purpose of using the super constructor with a props argument?

The below code snippets reveals that this.props behavior is different only within the constructor. It would be the same outside the constructor.

1
A child class constructor cannot make use of “this” reference until super() method has been called.
2
The main reason for passing the props parameter to super() call is to access this.props in your child constructors.
3
The same applies to ES6 sub-classes as well.
4
Access to this: In JavaScript, a child class constructor cannot make use of this until super() has been called. The same applies to React class components12. If you try to use this before super(), JavaScript will throw an error.
5
Inherit Parent Class Properties: The super() call is responsible for invoking the constructor of the parent class (in this case, React.Component). This allows your component to inherit methods from the parent class.

Passing props:

Not passing props:

Difficulty: 5/10

Topics: class components, props inheritance, constructor

0-2 years experience

1
If you create a React class component and forget to call super(props) in the constructor, what will happen when you try to read this.props?
2
Write the constructor for a class component that receives a title prop and stores it in state; include the super call.

2-5 years experience

1
You added a new prop to a parent component, but a child class component's this.props is undefined. Walk me through how you would debug this, focusing on the constructor.
2
Explain why you might still need to pass props to super even if you don't reference them directly in the constructor.

5-8 years experience

1
In a large codebase with many class components, we want to reduce boilerplate around constructors. How would you redesign a base component so subclasses don't need to call super(props) each time?
2
Consider a component that extends a custom BaseComponent which itself extends React.Component. Discuss the implications of calling super(props) in both constructors and any pitfalls.

8+ years experience

1
Our team is migrating legacy class components to functional components with hooks. How would you handle the semantics of super(props) during this migration to keep behavior consistent?
2
When designing a UI library that supports both class and functional components, what guidelines would you set regarding constructor usage and prop forwarding to maintain API stability across teams?