How Do Parentheses, Quotes, and No Quotes Affect `setTimeout` Behavior in JavaScript?

Understanding the Differences in setTimeout Usage

In JavaScript, setTimeout allows you to schedule a function to execute after a specified delay. There are several ways to use setTimeout with varying syntaxes.

1. with Parentheses:

setTimeout(() => console.log("Callback"), 1000);

In this scenario, an anonymous arrow function is passed as the callback, and the parentheses around it indicate that it's being executed immediately and passed as a reference to setTimeout.

2. Without Quotes or Parentheses:

setTimeout(callbackFunction, 1000);

Here, callbackFunction is a predefined function that is passed as the callback without any quotes or parentheses. The function reference is executed when the delay is complete.

3. Only Using Quotes:

setTimeout("alertMsg()", 1000);

This usage is strongly discouraged as it can lead to security vulnerabilities. It requires the function to be defined as a global variable and uses a string containing the function name. This string is then evaluated and executed as a script.

Key Differences:

• Parentheses: Indicate immediate execution of the callback function, passing it as a reference.
• Quotes: Allow a string containing the function name to be executed, but this is insecure.
• No Quotes or Parentheses: Pass the function reference directly as the callback.

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