JavaScript Fundamentals Quiz Quiz

1. Event Emitter Methods

   Which method is typically used to register a callback function to be executed when a specific event is emitted in an Event Emitter?

   1. trigger
   2. fire
   3. on
   4. listen
   5. attatch

2. Emit Function

   In an Event Emitter, what is the primary purpose of the 'emit' function?

   1. To register a new event listener.
   2. To remove an existing event listener.
   3. To execute all callback functions associated with a specific event.
   4. To define a new event.
   5. To clear all existing event

3. Remove Listener

   What is the purpose of the 'removeListener' method in an Event Emitter implementation?

   1. To create a new event.
   2. To permanently disable the event emitter.
   3. To detach a specific callback function from an event.
   4. To trigger all listeners for a specific event
   5. To pause event propagation

4. Closure in Javascript

   What does the term 'closure' refer to in JavaScript?

   1. The act of closing a file or stream.
   2. A function's ability to access variables from its surrounding scope, even after the outer function has finished executing.
   3. The process of minifying JavaScript code.
   4. The technique of preventing variable hoisting.
   5. The declaration of a class

5. Closure Example

   Given a function that returns another function, how does the inner function maintain access to variables from the outer function's scope after the outer function has returned?

   1. Through global variables.
   2. By creating copies of the variables.
   3. Through the prototype chain.
   4. Through closure, which preserves the outer function's scope.
   5. By using strict mode

6. Events object

   In a basic Event Emitter implementation, what data structure is commonly used to store the event names and their associated callback functions?

   1. A linked list.
   2. A stack.
   3. An object (hash map).
   4. A queue.
   5. An array

7. Callback Functions

   In JavaScript's Event Emitter pattern, what is the primary purpose of callback functions?

   1. To define new events.
   2. To handle errors.
   3. To execute code when a specific event occurs.
   4. To manage memory allocation.
   5. To prevent XSS attacks.

8. Event Listener Parameters

   In the 'emit' function of an Event Emitter, what is typically passed to the callback functions as an argument?

   1. The event name.
   2. The timestamp of the event.
   3. Event data or payload associated with the event.
   4. The emitter instance itself.
   5. The DOM element that triggered the event.

9. Asynchronous operations

   What common purpose do events serve in JavaScript?

   1. Garbage Collection
   2. Executing functions simulataneously
   3. Managing asynchronous operations
   4. Synchronizing Data
   5. Stopping Loops

10. Event Handling Mechanism

    Which describes the overall role of the Event Emitter pattern in JavaScript development?

    1. To provide a structured way to manage and respond to different application states or actions.
    2. To directly manipulate the DOM elements.
    3. To enforce synchronous operations in the code.
    4. To optimize memory usage.
    5. To create single threaded applications.