JS: Math (namespace)

By Xah Lee. Date: . Last updated: .

What is the Keyword “Math”

Math is the value of the property key "Math" of the Global Object .

console.log(globalThis["Math"] === Math);

Type

Type of Math is Object .

typeof Math === "object"

Parent

Parent of Math is Object.prototype.

Reflect.getPrototypeOf(Math) === Object.prototype

Purpose

Purpose of Math object is as a namespace for math related functions and constants.

Properties

Constants

Math.PI

π. Value is ≈ 3.1415

Math.E

Constant e. The number Limit[(1+1/n)^n,{n,∞}] . Value is ≈ 2.7182

Math.LN10

(new in JS: ECMAScript 2015) natural log of 10. Value is ≈ 2.3025

Math.LN2

natural log of 2. Value is ≈ 0.6931

Math.LOG10E

base-10 log of e. Value is ≈ 0.4342

Math.LOG2E

base-2 log of e. Value is ≈ 1.4426

Math.SQRT1_2

1/(√2). Value is ≈ 0.7071

Math.SQRT2

√2. Value is ≈ 1.4142

Math[Symbol.toStringTag]

(new in JS: ECMAScript 2015) value is the string "Math".

Common Math Functions

Math.max(args)

Return the largest of the arguments.

const xx = [24, 185, 53];
console.log(Math.max(...xx));
// 185
Math.min(args)

Return the smallest of the arguments. e.g. Math.min(...xArray)

Math.random()

Return a real number between 0 to 1, including 0 but excluding 1. 〔see Random Integer Function 📜〕

Math.sign(x)

Return 1 if x is positive, -1 if negative, 0 if positive 0, -0 if negative 0. (JavaScript's 0 can are signed. -0 === 0 eval to true.)

Math.abs(x)

Absolute value.

Ceiling, Floor, Round

Math.ceil(x)

Return a integer that's equal or greater than x.

Math.floor(x)

Return a integer that's equal or less than x.

Math.round(x)

Return a number to the nearest integer. 0.5 rounds up to 1.

Math.fround(x)

(new in JS: ECMAScript 2015) Return the nearest 32bits representation of x.

Math.trunc(x)

(new in JS: ECMAScript 2015) Return the integral part of x.

Power and Roots

Math.pow(x, y)
  • x raised to the power of y.
  • Same as x ** y.
Math.sqrt(x)

Square root.

Math.cbrt(x)

(new in JS: ECMAScript 2015) Cube root.

To compute nth root, use Math.pow(x, 1/n).

Exponential and Logarithm

Math.exp(x)

e raised to the power of x. Same as e ** x.

Math.expm1(x)

(new in JS: ECMAScript 2015) Same as e ** x -1. The result is computed in a way that is accurate even when the value of x is close 0.

console.log(Math.expm1(0.01));
// 0.010050167084168058

console.log(Math.pow(Math.E, 0.01) - 1);
// 0.010050167084167949
Math.log(x)

Natural log of x

Math.log10(x)

(new in JS: ECMAScript 2015) Base 10 log of x

Math.log1p(x)

(new in JS: ECMAScript 2015) Natural log of x+1

Math.log2(x)

(new in JS: ECMAScript 2015) Base 2 log of x

Trig

Math.sin(x)

Sine function.

Math.cos(x)

Cosine function.

Math.tan(x)

Tangent function.

Math.asin(x)

Inverse of sine. Domain is -1 to 1. Range is 0 to π.

Math.acos(x)

Inverse of cosine. Domain is -1 to 1. Range is 0 to π.

Math.atan(x)

Inverse of tangent. No restriction on domain. Range is -π/2 to π/2.

Math.atan2(y, x)

Return the arc tangent of the quotient y/x, where the signs of y and x are used to determine the quadrant of the result. Result is in range from −π to +π.

Math.hypot(x1, x2, etc)

(new in JS: ECMAScript 2015) Return the square root of (x1^2 + x2^2 + etc^2). This is useful to compute the length of a higher dimension vector in linear algebra.

All trig functions's argument are radians.

Hyperbolic Functions

Math.sinh(x)

(new in JS: ECMAScript 2015) Hyperbolic sine. That is (e^x - e^(-x))/2

Math.cosh(x)

(new in JS: ECMAScript 2015) hyperbolic cosine. That is (e^x + e^(-x))/2

Math.tanh(x)

(new in JS: ECMAScript 2015) Hyperbolic tangent. That is Sinh[x]/Cosh[x]

Math.asinh(x)

(new in JS: ECMAScript 2015) Inverse hyperbolic sine.

Math.acosh(x)

(new in JS: ECMAScript 2015) Inverse hyperbolic cosine.

Math.atanh(x)

(new in JS: ECMAScript 2015) Inverse hyperbolic tangent.

Misc

Math.clz32(x)

(new in JS: ECMAScript 2015) Return the number of leading zero bits in the 32-bit binary representation of x.

Math.imul(a, b)

(new in JS: ECMAScript 2015) multiplies a and b as though they were 32 bit signed integers.

JavaScript. Number