JavaScript Fundamentals: Understanding the Basics

Kosal Ang

Sun Jan 07 2024

JavaScript Fundamentals: Understanding the Basics

1. Introduction to JavaScript

JavaScript is a versatile scripting language primarily used for client-side web development. It enables interactivity and dynamic content on web pages.

1console.log("Hello, JavaScript!"); // Outputs text to the browser console
2

2. Data Types and Variables

JavaScript supports various data types like strings, numbers, booleans, arrays, and objects. Variables are declared using let, const, or var.

1let name = "Kosal"; // String variable
2let age = 25; // Number variable
3const isStudent = true; // Boolean variable
4

3. Operators and Expressions

JavaScript offers arithmetic, comparison, and logical operators to perform calculations and comparisons.

1let result = 10 + 5; // Addition operator
2let isEqual = 20 === 20; // Equality operator
3let isValid = (age >= 18) && (isStudent === false); // Logical AND operator
4

4. Control Structures: Conditionals and Loops

Control the flow of execution using if-else statements and loops.

1if (age >= 18) {
2  console.log("You are an adult.");
3} else {
4  console.log("You are a minor.");
5}
6
7for (let i = 0; i < 5; i++) {
8  console.log(`Count: ${i}`);
9}
10

5. Functions and Scope

Functions encapsulate blocks of code and can take parameters and return values.

1function greet(name) {
2  return `Hello, ${name}!`;
3}
4
5console.log(greet("Kosal")); // Outputs: Hello, Kosal!
6

6. Arrays and Objects

JavaScript arrays and objects allow storing collections of data and key-value pairs.

1let numbers = [1, 2, 3, 4, 5]; // Array
2let person = { name: "Kosal", age: 25, isStudent: true }; // Object
3
4console.log(numbers[2]); // Accessing array element
5console.log(person.name); // Accessing object property
6

These examples illustrate foundational JavaScript concepts, demonstrating how variables, operators, control structures, functions, arrays, and objects are used within JavaScript code.

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