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JavaScript Variables and Data Types

April 5, 2026

JavaScript Variables

Dynamically typed language with var, let, const declarations.

Variables Example

let name = "John";     // String
const age = 25;        // Number
var isActive = true;   // Boolean
let scores = [90, 85]; // Array
const person = {name: "John", age: 25}; // Object

Key Points

let: block-scoped, reassignable.
const: block-scoped, cannot reassign.
var: function-scoped (avoid in modern JS).
6 primitive types + Object.

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