What is the difference between `super()` and `super(props)` in React using ES6 classes?
Interviewer Expectations for this Question
01
Core Competency
Assesses fundamental understanding of React conventions, runtime behavior, and memory/performance considerations.
02
Evaluation Criteria
Hiring managers look for precision, avoidance of ambiguous jargon, and ability to explain trade-offs under real production conditions.
Comprehensive Model Answer
Verified Solution
When you want to access this.props in constructor() then you should pass props to super() method.
Using super(props):
class MyComponent extends React.Component {
constructor(props) {
super(props);
console.log(this.props); // { name: 'John', ... }
}
}
Using super():
class MyComponent extends React.Component {
constructor(props) {
super();
console.log(this.props); // undefined
}
}
Outside constructor() both will display same value for this.props.
Candidate Response Strategy & Interview Tips
- Start with a concise one-sentence summary: Deliver a direct, confident answer first before expanding into nuances.
- Demonstrate real-world trade-offs: Discuss where this approach excels and when you would avoid it in production systems.
- Discuss complexity & edge cases: Proactively explain time/space complexity or boundary conditions (null values, scale limits).
- Prepare for interviewer follow-ups: Technical hiring panels frequently probe deeper into concurrency, backward compatibility, or alternative libraries.