True or False: React was originally built by Facebook.

True or False: React encourages manipulating the real DOM directly for performance.

True or False: React uses a Virtual DOM to optimize updates.

True or False: In React, data flows from parent to child (one-way).

True or False: Components in React are always class-based; functional components are not allowed.

True or False: JSX is required to write React — you cannot use React without it.

True or False: React can be used to build mobile apps (via React Native).

True or False: When state changes in a component, React re-renders the entire application.

True or False: Props in React are immutable (cannot be changed by the component receiving them).

What is the main job of React as per the video?

Which of the following best describes “component” in React?

What does React compare during updates to decide which parts to update?

Which syntax allows mixing HTML-like tags in JavaScript in React?

How does React treat props passed into components?

What happens when you call setState or update state in a functional component (via hooks)?

Which of these is not part of React’s core idea?

Which of these would you use to pass data from a parent to child?

React’s Virtual DOM diff algorithm helps in:

Which of the following is a valid component declaration (functional) in React?

In React, keys in lists are used to:

Which hook is used to manage local state in functional components?

React’s reconciliation process refers to:

Which of these is a disadvantage or challenge of React (commonly discussed)?

Which of these is React not concerned with?

Suppose you have:
function Welcome(props) {

return <h1>Hello, {props.name}</h1>;}

Which is correct to use this in JSX?

Given:
const [count, setCount] = useState(0);
setCount(count + 1);
What happens when this executes in a click handler?

In a list rendering:
<ul>
{items.map((item, i) => {item})} Why might using i (index)

</ul>
Why might using i (index) as key be problematic?

Suppose a parent component passes a function prop:
<Child onClick={() => doSomething()} />
In Child, you call props.onClick() on a button click. That is an example of:

Which lifecycle does not exist in functional components?

If a component returns null in its render, what is displayed?

Which of these is equivalent to a class-based
this.setState({ count: 2 })
in functional?

Consider: <MyComp {...props} />

This is called:

If props.user is an object, you do:
<MyComp {...props.user} />

This passes:

Suppose you have two sibling components that share state. Best approach is:

What is the default return type of a functional component?

In React, event handlers are named using:

Which attribute corresponds to HTML’s class in JSX?

In JSX, to embed a JavaScript expression inside markup, you use:

Which hook lets you run side effects in functional components?

Suppose you want to ensure a component uses props only once and never changes them. You would:

In a class component, state is usually declared as:

What happens if keys are not provided for list elements in React?

If a parent component re-renders, child components will:

Scenario: You want to pass a callback into child that gives the child ability to update parent’s state. Which pattern is correct?

Suppose you have:
const element = <h1>Hello, world!</h1>;

What type is element?

React renders UI in response to:

If you call setState (or setter) many times in one event, React may batch updates. True or False?

You can conditionally render components in React by using:

Suppose you need global state across many components, you should use: