JS Exercises
Practise by changing the data before changing the algorithm. Find sessions with space and calculate their total available places.
Where to run this
This example uses the JavaScript console playground. Select Run to execute it; the example does not run on this lesson page.
Before you run it
Write down the result you expect and explain which line produces it. Then run the example and compare your reasoning with the result below.
A practical example
const sessions = [{places: 0}, {places: 3}, {places: 5}];
const total = sessions.filter(session => session.places > 0).reduce((sum, session) => sum + session.places, 0);
console.log(total);
What happens
The solution produces 8. First try writing the filter and reduce yourself.