Sharpen your skills in asynchronous programming by practicing the use of async/await, Promises, and callback functions. Dive into scenarios that require asynchronous operations, such as making API requests and delayed code execution.
All Practice Questions
Number of questions
28 questions
Total time
9 hours total
Questions List
1
DebounceImplement a function to limit how many times a function can be executed by delaying the execution of the function until after a specified time after its last execution attempt
Difficulty
Medium
Languages
JSTS
2
Promise.allImplement the Promise.all() function that resolves to an array of results if all the input elements are resolved or rejects otherwise
Difficulty
Medium
Languages
JSTS
3
Traffic LightBuild a traffic light where the lights switch from green to yellow to red after predetermined intervals and loop indefinitely
Difficulty
Medium
Available frameworks
4
Digital ClockBuild a 7-segment digital clock that shows the current time
Difficulty
Medium
Available frameworks
5
Job BoardBuild a job board that displays the latest job postings from Hacker News
Difficulty
Medium
Available frameworks
SleepImplement a function that pauses for a specified duration before resuming execution
Difficulty
Easy
Languages
JSTS
Cancellable IntervalImplement a function that acts like setInterval but returns a function to cancel the interval
Difficulty
Easy
Languages
JSTS
Cancellable TimeoutImplement a function that acts like setTimeout but returns a function to cancel the pending callback
Difficulty
Easy
Languages
JSTS
Promise.rejectImplement a function to return a Promise object rejected with a reason
Difficulty
Easy
Languages
JSTS
Promise.raceImplement the Promise.race() function that resolves or rejects when any of the input elements are resolved or rejected
Difficulty
Easy
Languages
JSTS
Progress BarsBuild a list of progress bars that fill up gradually when they are added to the page
Difficulty
Easy
Available frameworks
Promise MergeImplement a function to merge the results of two promises into a single value
Difficulty
Medium
Languages
JSTS
Promise.resolveImplement a function to resolve a given value to a Promise
Difficulty
Medium
Languages
JSTS
Promise TimeoutImplement a function that resolves a promise if it is fulfilled within a timeout period and rejects otherwise
Difficulty
Medium
Languages
JSTS
PromisifyImplement a function that takes a function following the common error-first callback style and returns a version that returns promises
Difficulty
Medium
Languages
JSTS
Promisify IIImplement a promisify function that allows the original function to override the return value
Difficulty
Medium
Languages
JSTS
ThrottleImplement a function to control the execution of a function by limiting how many times it can execute over time
Difficulty
Medium
Languages
JSTS
Debounce IIImplement a debounce function that comes with a cancel method to cancel delayed invocations and a flush method to immediately invoke them
Difficulty
Medium
Languages
JSTS
Promise.allSettledImplement the Promise.allSettled() function that resolves to an array of outcomes when all the input elements are either resolved or rejected
Difficulty
Medium
Languages
JSTS
Promise.anyImplement the Promise.any() function that resolves when any of the input elements are resolved
Difficulty
Medium
Languages
JSTS
Analog ClockBuild an analog clock where the hands update and move like a real clock
Difficulty
Medium
Available frameworks
Grid LightsBuild a grid of lights where the lights deactivate in the reverse order they were activated
Difficulty
Medium
Available frameworks
Like ButtonBuild a Like button that changes appearance based on the states
Difficulty
Medium
Available frameworks
Progress Bars IIBuild a list of progress bars that fill up gradually in sequence, one at a time
Difficulty
Medium
Available frameworks
Progress Bars IIIBuild a list of progress bars that fill up gradually concurrently, up to a limit of 3
Difficulty
Medium
Available frameworks
StopwatchBuild a stopwatch widget that can measure how much time has passed
Difficulty
Medium
Available frameworks
Whack-A-MoleBuild a popular arcade game where players attempt to hit moles as they pop up from holes in a board
Difficulty
Medium
Available frameworks
Progress Bars IVBuild a list of progress bars that fill up gradually concurrently, up to a limit of 3 and allows for pausing and resuming