JavaScript Basics

Like any programming language, JavaScript follows a specific syntax. It’s essential to structure your code correctly and understand the role of various elements. JavaScript code blocks are enclosed within curly braces {}, and each statement ends with a semicolon ;

// This is a single-line comment

/*
This is a multi-line
comment in JavaScript
*/

function greet() {
console.log(“Hello, World!”);
}

Variables are containers that store data in JavaScript. Unlike other programming languages, JavaScript is dynamically typed, meaning you don’t need to specify the data type explicitly.

let name = “Alice”; // String data type

let age = 25; // Number data type
let isStudent = true; // Boolean data type

JavaScript supports a variety of operators, including arithmetic, comparison, logical, and assignment operators. They allow you to perform mathematical operations, make comparisons, and handle logical conditions.

let num1 = 10;

let num2 = 5;

let sum = num1 + num2; // Addition
let isGreater = num1 > num2; // Comparison
let isTrue = true && false; // Logical AND

Control flow statements help you control the flow of execution based on certain conditions. The if-else statement and switch statement are commonly used in JavaScript.

let score = 85;

if (score >= 90) {
console.log(“Excellent!”);
} else if (score >= 70) {
console.log(“Good job!”);
} else {
console.log(“Keep practicing!”);
}

Loops are essential for repetitive tasks. JavaScript offers for, while, and do-while loops to iterate over data or execute code multiple times.

for (let i = 0; i < 5; i++) {

console.log(“Iteration: ” + i);
}

let count = 0;
while (count < 3) {
console.log(“Count: ” + count);
count++;
}

Functions in JavaScript are blocks of reusable code that can be invoked multiple times. They enable better code organization and modularity. JavaScript also has two types of scope: global and local.

function greetUser(name) {

console.log(“Hello, ” + name + “!”);
}

greetUser(“Bob”);