Full Stack Web Development MASTERY Course - Novice to Expert - Promises in JavaScript

This video tutorial introduces JavaScript promises, explaining their role in handling asynchronous operations. It covers the limitations of callbacks, the states of promises, and provides a practical example of creating and handling promises using resolve and reject. The tutorial concludes with the advantages of using promises over callbacks, highlighting improved error handling and code readability.

What is the primary purpose of promises in JavaScript?

• To handle synchronous operations

• To manage asynchronous operations

• To replace all functions

• To simplify variable declarations

Which of the following is NOT a state of a JavaScript promise?

• Pending

• Fulfilled

• Rejected

• Completed

What does the 'resolve' function signify in a promise?

• The promise is rejected

• The promise is fulfilled

• The promise is undefined

• The promise is pending

In the context of promises, what does the 'reject' function indicate?

• The promise is pending

• The promise is undefined

• The promise is fulfilled

• The promise is rejected

What is the role of the setTimeout function in the promise example?

• To simulate an asynchronous operation

• To reject the promise instantly

• To handle synchronous operations

• To immediately resolve the promise

What message is displayed if the promise operation is successful?

• Promise operation was unsuccessful

• No thanks

• Mission failed

• Promise operation is successful

What does the 'then' method do in a promise?

• It is called when the promise is undefined

• It is called when the promise is pending

• It is called when the promise is rejected

• It is called when the promise is fulfilled

What is the purpose of the 'catch' method in a promise?

• To handle rejected promises

• To handle pending promises

• To handle undefined promises

• To handle fulfilled promises

Which of the following is an advantage of using promises over callbacks?

• Promises are less reliable

• Promises are slower

• Promises improve code readability

• Promises are more complex

What happens if the error variable is set to false in the promise example?

• The promise is rejected

• The promise remains pending

• The promise is fulfilled

• The promise is undefined