MathMath is an object with data properties and methods for processing numbers. You can see it as a poor man’s module: It was created long before JavaScript had modules.
Math.E: number [ES1]
Euler’s number, base of the natural logarithms, approximately 2.7182818284590452354.
Math.LN10: number [ES1]
The natural logarithm of 10, approximately 2.302585092994046.
Math.LN2: number [ES1]
The natural logarithm of 2, approximately 0.6931471805599453.
Math.LOG10E: number [ES1]
The logarithm of e to base 10, approximately 0.4342944819032518.
Math.LOG2E: number [ES1]
The logarithm of e to base 2, approximately 1.4426950408889634.
Math.PI: number [ES1]
The mathematical constant π, ratio of a circle’s circumference to its diameter, approximately 3.1415926535897932.
Math.SQRT1_2: number [ES1]
The square root of 1/2, approximately 0.7071067811865476.
Math.SQRT2: number [ES1]
The square root of 2, approximately 1.4142135623730951.
Math.cbrt(x: number): number [ES6]
Returns the cube root of x.
Math.exp(x: number): number [ES1]
Returns ex (e being Euler’s number). The inverse of Math.log().
Math.expm1(x: number): number [ES6]
Returns Math.exp(x)-1. The inverse of Math.log1p(). Very small numbers (fractions close to 0) are represented with a higher precision. Therefore, this function returns more precise values whenever .exp() returns values close to 1.
Math.log(x: number): number [ES1]
Returns the natural logarithm of x (to base e, Euler’s number). The inverse of Math.exp().
Math.log1p(x: number): number [ES6]
Returns Math.log(1 + x). The inverse of Math.expm1(). Very small numbers (fractions close to 0) are represented with a higher precision. Therefore, you can provide this function with a more precise argument whenever the argument for .log() is close to 1.
Math.log10(x: number): number [ES6]
Returns the logarithm of x to base 10. The inverse of 10 ** x.
Math.log2(x: number): number [ES6]
Returns the logarithm of x to base 2. The inverse of 2 ** x.
Math.pow(x: number, y: number): number [ES1]
Returns xy, x to the power of y. The same as x ** y.
Math.sqrt(x: number): number [ES1]
Returns the square root of x. The inverse of x ** 2.
Rounding means converting an arbitrary number to an integer (a number without a decimal fraction). The following functions implement different approaches to rounding.
Math.ceil(x: number): number [ES1]
Returns the smallest (closest to −∞) integer i with x ≤ i.
Math.floor(x: number): number [ES1]
Returns the largest (closest to +∞) integer i with i ≤ x.
Math.round(x: number): number [ES1]
Returns the integer that is closest to x. If the decimal fraction of x is .5 then .round() rounds up (to the integer closer to positive infinity):
Math.trunc(x: number): number [ES6]
Removes the decimal fraction of x and returns the resulting integer.
Tbl. 12 shows the results of the rounding functions for a few representative inputs.
-2.9 |
-2.5 |
-2.1 |
2.1 |
2.5 |
2.9 |
|
|---|---|---|---|---|---|---|
Math.floor |
-3 |
-3 |
-3 |
2 |
2 |
2 |
Math.ceil |
-2 |
-2 |
-2 |
3 |
3 |
3 |
Math.round |
-3 |
-2 |
-2 |
2 |
3 |
3 |
Math.trunc |
-2 |
-2 |
-2 |
2 |
2 |
2 |
All angles are specified in radians. Use the following two functions to convert between degrees and radians.
function degreesToRadians(degrees) {
return degrees / 180 * Math.PI;
}
assert.equal(degreesToRadians(90), Math.PI/2);
function radiansToDegrees(radians) {
return radians / Math.PI * 180;
}
assert.equal(radiansToDegrees(Math.PI), 180);Math.acos(x: number): number [ES1]
Returns the arc cosine (inverse cosine) of x.
Math.acosh(x: number): number [ES6]
Returns the inverse hyperbolic cosine of x.
Math.asin(x: number): number [ES1]
Returns the arc sine (inverse sine) of x.
Math.asinh(x: number): number [ES6]
Returns the inverse hyperbolic sine of x.
Math.atan(x: number): number [ES1]
Returns the arc tangent (inverse tangent) of x.
Math.atanh(x: number): number [ES6]
Returns the inverse hyperbolic tangent of x.
Math.atan2(y: number, x: number): number [ES1]
Returns the arc tangent of the quotient y/x.
Math.cos(x: number): number [ES1]
Returns the cosine of x.
Math.cosh(x: number): number [ES6]
Returns the hyperbolic cosine of x.
Math.hypot(...values: number[]): number [ES6]
Returns the square root of the sum of the squares of values (Pythagoras’ theorem):
Math.sin(x: number): number [ES1]
Returns the sine of x.
Math.sinh(x: number): number [ES6]
Returns the hyperbolic sine of x.
Math.tan(x: number): number [ES1]
Returns the tangent of x.
Math.tanh(x: number): number; [ES6]
Returns the hyperbolic tangent of x.
Math.abs(x: number): number [ES1]
Returns the absolute value of x.
Math.clz32(x: number): number [ES6]
Counts the leading zero bits in the 32-bit integer x. Used in DSP algorithms.
Math.max(...values: number[]): number [ES1]
Converts values to numbers and returns the largest one.
Math.min(...values: number[]): number [ES1]
Converts values to numbers and returns the smallest one.
Math.random(): number [ES1]
Returns a pseudo-random number n where 0 ≤ n < 1.
Computing a random integer i where 0 ≤ i < max:
Math.sign(x: number): number [ES6]
Returns the sign of a number: