concepts

Math Object

JavaScript Math object provides properties and methods for mathematical operations.

Math

• Math.PI returns 3.14159

• Math.round(1.2) rounds to the nearest integer

• Math.floor(1.2) rounds down to the nearest integer

• Math.ceil(1.2) rounds up to the nearest integer

• Math.sqrt(100) returns the square root of x

• ...and many more.

Math Object vs. Math Operations

• Object: for specialized/complex mathematical operations and constants (e.g., Math.PI).

• Operations: built-in operators for basic calculations like addition, subtraction, multiplication, etc.

Example — basic operations:

basic-operators.js

let sum = 5 + 3;          // Addition
let difference = 10 - 4;  // Subtraction
let product = 6 * 7;      // Multiplication
let quotient = 15 / 3;    // Division
let remainder = 10 % 3;   // Modulus (remainder)
let power = 2 ** 3;       // Exponentiation (ES2016+)

Example — Math object usage:

math-object.js

let squareRoot = Math.sqrt(16);        // Square root
let rounded = Math.round(4.7);         // Rounding
let randomNumber = Math.random();      // Random number
let piValue = Math.PI;                 // Mathematical constant
let maxValue = Math.max(5, 10, 15);    // Finding maximum
let sineValue = Math.sin(Math.PI / 2); // Trigonometry

random() method

Math.random() returns a pseudo-random number between 0 (inclusive) and 1 (exclusive).

• Math.random() gives you a random decimal number between 0 and 1

• Includes 0 but never exactly 1

• No parameters. Method is called without any arguments

  • ✅ Correct: Math.random()

  • ❌ Incorrect: Math.random(123)

You can scale the result by multiplying:

random-scale.js

// Decimal between 0 and 10 (10 exclusive)
Math.random() * 10

To convert to integers, use rounding:

• Rounding down with Math.floor(Math.random() * 10) returns integers 0, 1, 2, ... 9

• Rounding up with Math.ceil(Math.random() * 10) returns integers 0, 1, 2, ... 10

Remember: multiplying Math.random() by N yields a decimal in [0, N). Rounding behavior determines the inclusive/exclusive range for integers.

References

• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math

• https://codehs.com/tutorial/ryan/math-object-in-javascript

• https://javascript.info/number#other-math-functions