⚡️ Fire on Push: Dispatching Custom Events When an Array Changes in JavaScript
Category: js / utils
Difficulty: medium
JavaScript arrays are powerful—but they don’t emit events . Want to react when someone .push()es a new item? You’re out of luck... unless you take control. This post shows you how to intercept array mutations and dispatch custom events when push() is called — all in vanilla JavaScript, no frameworks, no proxies. 🧪 The Goal We want to monitor this: [code example] And react like this: [code example] 🛠 Step 1: Custom Array Wrapper [code example] 🚀 Usage [code example] 🎯 Why This Works We're overriding push() on a per-array basis We preserve original functionality via Array.prototype.push.apply(...) We dispatch a CustomEvent with rich detail 🧠 Bonus: Generalizing for Other Methods Want to observe pop, shift, or even splice? Here’s a sketch: [code example] [code example] 🧬 Alternative: Using Proxies (Advanced) Want a more general-purpose reactive array? Use a Proxy. It’s more powerful but less performant:...