Why Does My `setTimeout` Function Run Immediately?

Why Does setTimeout Run My Function Immediately?

When using setTimeout, you may encounter a scenario where the specified waiting time is ignored, causing the function to execute instantly. This behavior arises from a common misconception in the syntax used.

The Pitfall:

The code snippet below demonstrates the issue:

setTimeout(testfunction(), 2000);

The Explanation:

In the code, testfunction() is being invoked immediately using parentheses. This means that setTimeout is scheduled to wait for the result of testfunction(), which is executed instantaneously.

The Solution:

To ensure that setTimeout waits for the desired time before executing the function, use this syntax instead:

setTimeout(testFunction, 2000);

Note the absence of parentheses after testFunction. By omitting the parentheses, you pass the reference to the function itself, not the result of calling it.

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