Odin项目JavaScript井字棋课程中gameBoard模块addEventListener自动生效原因咨询

Hey there! Let's break down what's going on with your code step by step:

First, let's look at your code block:

const gameBoard = (() => { 
  window.addEventListener("click", () => { alert("2") }) 
})()

The (() => { ... })() part is an Immediately Invoked Function Expression (IIFE) — this fancy term just means the function inside runs right away as soon as your browser parses this line of code.

What the IIFE does here is call window.addEventListener("click", ...): this is just registering (binding) the click event listener to the window object. Important note: binding the listener doesn't trigger the alert("2") yet — it just tells the browser, "Hey, if anyone clicks anywhere on the page later, run this alert code."

Wait, but you said it's activating automatically? A couple of possible reasons you might be seeing that alert pop up without clicking:

• Maybe you accidentally clicked the page right after the code loaded (it happens to the best of us!) — the listener is ready as soon as the IIFE runs, so even a tiny accidental click will trigger it.
• If you're running this code in an environment where the window's click event is being simulated (like some testing tools or browser extensions), that could also cause it. But in a regular browser tab, this shouldn't happen on its own.

To test this properly, reload the page and don't click anything — you won't see the alert until you intentionally click somewhere on the page. The listener itself is just being set up immediately, not triggered immediately.

If you only want the listener to be added after a specific user action (like clicking a "start game" button), you'd wrap the addEventListener call inside another function that gets triggered later, instead of putting it directly in the IIFE.

内容的提问来源于stack exchange，提问作者Risto Libera