TryHackMe — JavaScript Essentials | Cyber Security 101 (THM)

Essential Concepts

• Variables: Containers for storing data in JavaScript. Declare with var (function-scoped), let, or const (both block-scoped) for controlled visibility.
• Data Types: Define value types for variables, like string, number, boolean, null, undefined, and object (e.g., arrays).
• Functions: Code blocks for specific tasks. Instead of repeating code, use functions like PrintResult(rollNum) to manage repeated actions.
• Loops: Run code multiple times while a condition is true, using loops like for, while, and do...while.
• Request-Response Cycle: A client sends a request, and the server responds with resources (e.g., a webpage).

Questions and Answers

1. What term allows you to run a code block multiple times as long as it is a condition?

• Loop

JavaScript Overview

JavaScript (JS) is an interpreted language that runs directly in the browser. Here’s a breakdown of key concepts in a sample JS program:

• Hello, World!: A simple log to the console.
• Variables and Data Types: Define values, e.g., let age = 25;.
• Control Flow: Uses if statements to execute different code based on conditions.
• Functions: Code blocks like greet(name) that can be reused.