Quiz for Handling Events in React

Q1: What is the correct way to handle a click event in React?

A. onClick={handleClick()} B. onClick="handleClick" C. onClick={handleClick} D. click={handleClick}

Q2: Which of the following is true about event handling in React?

A. Events are named using lowercase B. You cannot use arrow functions C. Event handlers are passed as strings D. Events are named using camelCase

Q3: How do you prevent default behavior in a React event handler?

A. e.stopDefault() B. event.prevent() C. e.preventDefault() D. event.stopPropagation()

Q4: What does e.target represent in an event handler?

A. The element that was clicked B. The value returned by the handler C. The event handler function D. The event name

Q5: What is the purpose of binding "this" in class components?

A. To increase performance B. To access the correct context inside event handlers C. To prevent memory leaks D. To avoid re-rendering

Q6: Which is the correct way to pass a parameter to an event handler in React?

A. onClick={this.handleClick(param)} B. onClick={() => this.handleClick(param)} C. onClick={handleClick(param)} D. onClick={function(param)}

Q7: What happens if you call a function instead of passing it in an event handler?

A. It works the same B. It throws an error C. It executes immediately on render D. It delays execution

Q8: Which React method is used to bind an event handler in a class component?

A. bindEvent() B. attach() C. bind() D. setHandler()

Q9: What is synthetic event in React?

A. A fake event B. A wrapper around the browser's native event C. A manual event created by the user D. An event triggered on state change

Q10: Which is the correct syntax to stop event propagation in React?

A. e.stop() B. e.stopPropagation() C. event.stop() D. e.preventPropagation()

Q11: How does React handle events internally?

A. It uses DOM event delegation B. It attaches events directly to each element C. It compiles to jQuery D. It stores events in Redux

Q12: What is the correct way to handle a form submission in React?

A. onSubmit="handleSubmit" B. onSubmit={handleSubmit()} C. onSubmit={handleSubmit} D. submit={handleSubmit}

Q13: Which method is used to access input value in event handler?

A. e.inputValue B. e.target.value C. e.value D. e.input.value()

Q14: What is the advantage of using arrow functions for event handlers?

A. Better performance B. Simpler syntax C. No need to bind "this" D. All of the above

Q15: What does the event object represent?

A. A timer object B. A function pointer C. The state of the component D. Information about the triggered event

Q16: Which hook is commonly used for handling events in functional components?

A. useRef B. useEffect C. useState D. useCallback

Q17: What happens if you do not bind "this" in a class component?

A. It automatically binds B. Nothing C. The function loses its context D. It throws syntax error

Q18: How are keyboard events handled in React?

A. onKeyDown, onKeyUp B. onKeyboard C. keyEvent D. onType

Q19: Can we use inline event handlers in React?

A. No, it's not allowed B. Yes, using arrow functions or function references C. Only with useEffect D. Only in class components

Q20: Which of the following is not a valid React event?

A. onClick B. onChange C. onMouseEnter D. onSubmitClick