Salesforce JavaScript Developer Practice Exam

What does the setInterval method return in the browser?

1. a unique id

2. the amount of milliseconds specified

3. the passed function

4. undefined

The correct answer is: a unique id

The setInterval method returns a unique identifier for the timer that it creates. This identifier is a numeric value that can be used later to clear the interval using the clearInterval method. When setInterval is called, it repeatedly invokes a specified function at defined intervals (in milliseconds). The unique ID returned allows developers to manage the intervals effectively, for instance, to stop the repeated execution of a function when it is no longer needed. While other options may hold some relevance, they do not accurately describe the return value of the setInterval method. The method does not return the amount of milliseconds specified, the passed function, or undefined. Instead, it specifically provides a handle that is essential for managing the timer's execution in the browser.