RxJS Online Test
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About the test
The RxJS online test assesses knowledge of reactive programming concepts with RxJS and the various prebuilt operators that come with the library.
The assessment includes work-sample tasks such as:
- Using RxJS Observables to manage asynchronously created data.
- Working with RxJS Subjects for data broadcasting.
- Processing streams of data with Pipeable Operators.
A good RxJS developer should be able to use reactive programming and the various prebuilt operators that come with the RxJS library to create maintainable and accessible web user interfaces.
Sample public questions
An online streaming platform uses the following RxJS code to log the number of seconds passed in a video:
const seconds = interval(1000).pipe(
map((x) => x + 1),
startWith(0)
);
const logger = seconds.subscribe((x) =>
console.log(`Seconds passed: ${x}`)
);
setTimeout(() => {
logger.unsubscribe();
}, 5000);
What options will be true about seconds for the code above?
Consider the following RxJS code for pushing and logging weather data:
const weatherSubject = new _______________({temperature: 0 , rainChance: 0});
const sendWeatherData = (weatherData) => {
weatherSubject.____(weatherData);
};
sendWeatherData({temperature: 35.5 , rainChance: 20});
sendWeatherData({temperature: 34 , rainChance: 25});
weatherSubject.subscribe((x) => {
console.log("Current Temperature: " + x.temperature);
});
sendWeatherData({temperature: 28 , rainChance: 50});
weatherSubject.subscribe((x) => {
console.log("Chance of rain: " + x.rainChance);
});
sendWeatherData({temperature: 25 , rainChance: 90});
Fill in the blanks above so that the following output is produced after running it:
Current Temperature: 34
Current Temperature: 28
Chance of rain: 50
Current Temperature: 25
Chance of rain: 90
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Log Post Data, Dictionary Definition, Fresh Food, Awesome Tracking.
Skills and topics tested
- RxJS
- RxJS Observable
- Creation Operator
- Pipeable Operator
- Bug Fixing
- RxJS Subject
For job roles
- RxJS Developer
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Simple, straight-forward technical testing
TestDome is simple, provides a reasonable (though not extensive) battery of tests to choose from, and doesn't take the candidate an inordinate amount of time. It also simulates working pressure with the time limits.
Jan Opperman, Grindrod Bank
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