Review (Quiz)

Review (Quiz)

This lesson contains all of the recap quizzes from all of the lessons in this module. I have added headers to each group of quizzes so that you know which lesson to go back and study if you get stuck. Good luck!

What is an Observable?

Which of the following is NOT a reasonable description of the observer pattern?

1. A way to connect a producer of values to observers of those values

2. A way to notify one or more observers of multiple values emitted over time

3. A way to break up data and stream it in “chunks” to improve performance

Check

What methods does an Observer implement?

1. notify, subscribe, delete

2. next, error, complete

3. next, subscribe, unsubscribe

Check

How do we pass an Observer to an Observable?

1. By calling the next method

2. By passing it to the subscribe method of the observable

3. By creating a new instance of an observable and passing it through the constructor

Check

Which of the following is NOT the role of an Observable?

1. To produce values to pass to an observer

2. To define what to do with values that are produced

3. To call the next method on an observer when a new value is produced

Check

What is one key difference between cold/unicast and hot/multicast observables?

1. Cold observables produce values from within the observable, hot observables produce values from outside of the observable stream

2. Cold observables only produce one value, hot observables can produce multiple values over time

3. Hot observables are more performant than cold observables

Check

A (standard) Observable is a…

1. Cold/unicast observable

2. Hot/multicast observable

Check

A Subject is a…

1. Cold/unicast observable

2. Hot/multicast observable

Check

How do we define the value production logic for a cold Observable?

1. By supplying a function that accepts an observer to the “next” method

2. By supplying a function that accepts an observer when creating an new instance of an Observable

3. By calling the next method from outside of the observable

Check

How do we define the value production logic for a hot Observable (e.g. a Subject)?

1. By calling the next method from outside of the Subject

2. By supplying a function that accepts an observer when creating an new instance of a Subject

3. By supplying a function that accepts an observer to the next method

Check

An Introduction to RxJS

What are the two types of operators RxJS provides?

1. Hot operators and cold operators

2. Creation operators and pipeable operators

3. Observable operators and subject operators

Check

What does a creation operator do?

1. Accepts some input and creates a new observable based on that input

2. Subscribes to an observable and returns a new observable

3. Modifies an observable stream in some way

Check

What does a pipeable operator do?

1. Modifies an existing stream to return new values

2. Accepts some input and returns a new observable

Check

Which of the following is the correct usage of a pipeable operator?

1. someStream$.map().tap()

Check