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JavaScript Variables and Data Types

Variables in JavaScript are containers for storing values, such as numbers, strings, or objects. Variables are declared using the var, let, or const keyword.
var x;
x = 10;
let y = 20;
const z = 30;

In the above examples, var x declares a variable x, let y = 20 declares a variable y and assigns a value of 20 to it, and const z = 30 declares a constant variable z with a value of 30.

JavaScript has several data types, including:

  1. Number: Used to represent numeric values, including integers and floating-point numbers.
let num = 10;
  1. String: Used to represent text, denoted by either single or double quotes.
let str = "Hello World";
  1. Boolean: Used to represent true or false values.
let flag = true;
  1. Undefined: A value that has not been assigned to a variable.
let name;
console.log(name); // undefined
  1. Null: A value that explicitly represents the absence of a value.
let person = null;
  1. Object: A complex data type used to store collections of data and functions.
let obj = { name: "John", age: 30 };
  1. Array: An ordered list of values, denoted by square brackets [].
let arr = [1, 2, 3, 4];


Next: JavaScript Arrays

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