JS TutorialLesson 17Free preview

JS Timers

This lesson is part of JavaScript · All levels

Summary

JavaScript provides a timer to run code after a certain pause with setTimeout or repeatedly with setInterval. Both work asynchronously based on milliseconds, so that other code stays running while waiting for its time to arrive. Timers can be canceled with clearTimeout and clearInterval using the id returned when the timer was created.

Key points

Run the function once after a millisecond break
Running a repeating function every millisecond break
Both functions return the id that can be used to cancel the timer.
Asynchronous timers: statements after the setTimeout remained executed first

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