React Components 2

Question 1

What is the children prop in React?

Accepted Answer

The content placed between the opening and closing tags of a component, accessible via props.children

Answer

props.children contains whatever is placed between a component's opening and closing tags, enabling component composition patterns.

Question 2

What is conditional rendering in React?

Accepted Answer

Showing different UI elements based on conditions using JavaScript operators like if, ternary, or &&

Answer

Conditional rendering uses JavaScript logic within JSX to determine which elements to display based on state, props, or other conditions.

Question 3

What is a controlled component?

Accepted Answer

A form element whose value is controlled by React state rather than the DOM

Answer

In controlled components, React state is the single source of truth for form inputs. Every change updates state, and state drives what is displayed.

Question 4

What is prop drilling?

Accepted Answer

Passing props through multiple intermediate components that do not need them, just to reach a deeply nested child

Answer

Prop drilling occurs when data must pass through many component layers. Solutions include Context API, state management libraries, or component composition.

Question 5

What are keys in React lists?

Accepted Answer

Unique identifiers that help React identify which list items have changed, been added, or removed

Answer

Keys help React's reconciliation algorithm efficiently update lists by identifying individual elements. They should be stable, unique, and predictable.

React Practice Test

React Practice Test

React Components 2