JavaScript Syntax Essentials

JavaScript syntax is the set of rules defining how JavaScript code should be written.

1. Variables

Variables are used to store data values. In JavaScript, there are three main ways to declare a variable:

• let: Allows block-scoped variables that can be updated.
• const: Declares block-scoped variables that cannot be updated.
• var: Declares function-scoped variables (now less commonly used).

let name = "Alice";   // Using let
const age = 25;     // Using const
var city = "New York"; // Using var

2. Data Types

JavaScript supports several data types for storing different types of values. Common data types include:

• String: Represents text, enclosed in quotes.
• Number: Represents both integer and floating-point numbers.
• Boolean: Represents true/false values.

let greeting = "Hello"; // String
let count = 10;         // Number
let isLoggedIn = true;  // Boolean

3. Basic Operators

Operators are symbols used to perform operations on variables and values. Here are some common types:

• Arithmetic operators: + (addition), - (subtraction), * (multiplication), / (division).
• Assignment operators: =, +=, -=, etc.
• Comparison operators: ==, ===, !=, !==, etc.

let sum = 5 + 3;        // Addition
let isEqual = (5 === 5); // Logical comparison