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September 2023 (514 Words, 3 Minutes)

Week 5 Review Ticket: HTML Basics and JavaScript Fundamentals

In this review, we will cover essential concepts related to HTML and JavaScript fundamentals.

HTML Basics

HTML, which stands for HyperText Markup Language, is the backbone of web development. It uses opening and closing tags to structure content. Key HTML elements include:

• Paragraph: <p></p>
• Link: <a href="https://www.w3schools.com/html/default.asp">Visit W3Schools HTML Page</a>
• Image: <img alt="describe image" src="link to image" width="100" height="200">
• Bold text: <strong>Bolded Text</strong>
• Italics: <i>Italic Text</i>
• Button: <button>some button text</button>

JavaScript Data Types

JavaScript, a versatile programming language, offers various data types:

• String Data Type: Used for storing text. You can perform string manipulation using functions like toUpperCase(), toLowerCase(), and substring().
• Number Data Type: For storing numerical values. You can perform mathematical operations and formatting.
• Array Data Type: Lists used to store multiple values. You can access array elements by their index and use functions like push() and pop().
• Object Data Type: Objects store data as key-value pairs, enabling you to create structured data. Considerations include object literals and constructor functions.

Using JavaScript with HTML DOM

Working with the Document Object Model (DOM) allows you to interact with HTML elements dynamically. Some key points:

• Workspace Update: Always run git pull to stay updated in a collaborative coding environment.
• Referencing HTML Elements: Use document.getElementById("idTag") to reference elements by their unique IDs. The .innerHTML attribute allows access and modification of content within tags.
• Element Creation & Insertion: Use document.createElement(type) to create elements programmatically. The .appendChild(element) method adds elements to the HTML structure.
• Utilizing Functions: Functions are essential for code organization and reusability. They can take parameters and return values. Events, such as button clicks, can trigger these functions.

Basics of JavaScript

JavaScript is commonly used for adding interactivity to web pages. Some foundational concepts:

• Embedding JavaScript: You can embed JavaScript within HTML using the <script> tag or in Jupyter cells using the %%html magic command.
• Console Logging: Use console.log() to print messages to the browser’s console. You can access the console through the browser’s developer tools.
• Data Storage & Types: JavaScript provides basic data types like strings, numbers, and booleans. You declare variables using var, let, or const.
• Data Access & Manipulation: Access and manipulate data by referencing variable names. For strings, you can use operators like + for concatenation.
• Number Operations: Perform arithmetic operations and comparisons. Use == for value comparison and === for type and value comparison.
• Conditional Statements: Use if-else statements for conditional execution of code blocks. Combine with operators for dynamic comparisons and responses.

JavaScript Errors

Let’s review and improve code segments to address common issues:

Segment 1: Alphabet List

Intended Behavior: Create a list of characters from the string contained in the variable alphabet.

What I Changed: The for loop’s condition should be i < alphabet.length to iterate over each character in alphabet. Instead of pushing i, which is a number, push alphabet[i] to add each character to alphabetList.

Segment 2: Numbered Alphabet

Intended Behavior: Print the number and corresponding character in alphabet based on letterNumber.

What I Changed: Adjusted the loop’s condition and corrected the console.log statement for accurate output.

Segment 3: Odd Numbers

Intended Behavior: Print all odd numbers below 10.

What I Changed: Adjusted the initialization and incrementation of i to produce odd numbers correctly.

Challenge Segment: Cost Calculator

Goal: Error-proof the code and implement a user input test.

What to Do: Develop tests for user inputs and expected outputs. Gradually implement features to pass these tests. Iterate until the program functions as expected.

This review ticket serves as a reference for understanding HTML basics, JavaScript data types, DOM manipulation, and common code debugging practices. Happy coding!