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Variables and Data Types

Variables in JavaScript are containers used to store data values. You can declare variables using var, let, or const:

  • var: Function-scoped, hoisted, rarely used in modern code.
  • let: Block-scoped, can be reassigned.
  • const: Block-scoped, cannot be reassigned.

Example:

let name = 'Alice';
const age = 25;
var isStudent = true;

JavaScript Data Types:

  • Primitive Types: string, number, boolean, undefined, null, symbol, bigint
  • Reference Types: objects, arrays, functions

Use typeof to check the type of a variable:

console.log(typeof name); // 'string'
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