Day15

Day 15 – JavaScript Control Flow & DOM 🎯

Today’s class was rushed because the lecture was moving fast, so I made quick notes. Let’s make them more structured and detailed.

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📚 Topics Covered

1. Writing Simple JS Scripts

• Even/Odd Numbers – Check if a number is even or odd.
• Array of Numbers – Iterate through an array.
• Divisible by 5 – Print numbers divisible by 5.

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2. DOM Manipulation

We started learning how to select and edit HTML elements using JavaScript.

Old Way:

const myHeading = document.getElementById("Heading");
myHeading.textContent = "Manvith";
myHeading.style.color = "white";

Modern Way (Preferred):

const myHeading = document.querySelector("#Heading");
myHeading.textContent = "Manvith";
myHeading.style.color = "white";

⚡ getElementById still works but querySelector is now the industry standard because it’s more flexible (can select by id, class, tag, etc.).

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🏗️ Control Flow & DOM in Practice

• Control Flow helps us run conditions (if/else, loops) to decide how scripts behave.
• DOM (Document Object Model) lets us interact with and change HTML elements using JavaScript.

Example:

for (let i = 1; i <= 20; i++) {
    if (i % 2 === 0) {
        console.log(i + " is Even");
    } else {
        console.log(i + " is Odd");
    }
}

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📝 Homework

We had to:

1. Create a heading named Java in HTML.
2. Select the element and change it to JavaScript.
3. Apply some styling.
4. Add Java information.
5. Then remove that Java info and add JavaScript info using createElement.

✅ My Homework File

Homework

📂 Folder Structure

Day15/
│
├── controlflow/     # Notes & practice files for control flow (if-else, loops, switch)
│
├── DOM/             # Notes & practice files for Document Object Model manipulations
│
├── Homework/        # Assigned exercises and completed solutions
│
└── README.md        # Summary of Day 15 learning and tasks