DataTypes Notebook

DataTypes

JavaScript has 8 data types.

Basic 8 types: String, Number, Bigint, Boolean, Undefined, Null, Symbol, Object
Object types: objects, arrays, dates, maps, sets, intarrays, floatarrays, promises, and more.

IN [9]

let x = 16 + "Volvo"; // OR "Volvo" + 16;
let y = 16 + 4 + "Volvo";
let z = "Volvo" + 16 + 4;

console.log("x: " + x + " and y: " + y + " and z: " + z);

IN [12]

// Dynamic types
let x;       // Now x is undefined
x = 5;       // Now x is a Number
x = "John";  // Now x is a String
console.log(typeof x);

IN [14]

// Exponentials
let y = 123e5;    // 12300000
let z = 123e-5;   // 0.00123

Javascript numbers are always one type: double (64-bit floating point).

IN [17]

let x = BigInt("123456789012345678901234567890");
console.log(typeof x + " " + x + " length: " + x.toString().length);

IN [18]

typeof 3.14

IN [21]

// car = undefined;
console.log(typeof undefined);

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