Salesforce JavaScript Developer Practice Exam

What will be the output of the code snippet that uses var within a setTimeout?

1. 0 1 2 and 0 1 2

2. 0 1 2 and 3 3 3

3. 3 3 3 and 0 1 2

4. 3 3 3 and 3 3 3

The correct answer is: 3 3 3 and 0 1 2

The behavior of the code snippet involving the use of the `var` keyword inside a `setTimeout` function is crucial for understanding the output. When you declare a variable using `var`, it is function-scoped, meaning that if it is defined inside a function, it is available within that entire function, and if it is defined outside, it is available throughout the entire script. In a typical scenario where you have a loop that sets a timeout, the variable is shared across all iterations of the loop. Consequently, by the time the timeout executes, the loop has completed and the loop variable holds its final value. If the loop iterates three times, for instance, at the end of those iterations, the loop variable would be equal to 3. Hence, when the `setTimeout` function executes, it accesses the shared loop variable, which has already been updated to this final value. As a result, all timeouts that get triggered after the delay will utilize the latest value of the loop variable, producing the output of 3 for each timeout. Thus, if the code snippet is set up to call `console.log` within the `setTimeout`, you would see the output of 3 printed multiple times, corresponding to the