🧠 JavaScript Event Listeners & Timers

1. onClick

Jab user kisi button ya element par click karta hai, to `onClick` event trigger hota hai.

function handleClick() {
  alert("Button clicked!");
}

<button onClick={handleClick}>Click Me</button>

2. onBlur

`onBlur` tab chalta hai jab kisi input field se focus remove hota hai (e.g. user bahar click kare).

<input type="text" onBlur={() => alert("Input lost focus")} />

3. onChange

`onChange` tab fire hota hai jab input ka value change hota hai.

function handleChange(e) {
  console.log("Input:", e.target.value);
}

<input type="text" onChange={handleChange} />

4. onFocus

`onFocus` tab chalta hai jab user kisi input pe click kare ya tab kare.

<input type="text" onFocus={() => console.log("Input focused")} />

5. setTimeout()

`setTimeout` ek bar delay ke baad code run karta hai.

setTimeout(() => {
  console.log("3 second ke baad run hua");
}, 3000);

6. setInterval()

`setInterval` bar bar code run karta hai har kuch milliseconds ke interval pe.

setInterval(() => {
  console.log("Har 2 second me run ho raha hai");
}, 2000);