Math

Math is a little different from the other built-in objects, because it cannot be used as a constructor to create objects. It is just a collection of functions and constants. Some examples, to illustrate the difference, are given below:

>>> typeof String.prototype

"object"

>>> typeof Date.prototype

"object"

>>> typeof Math.prototype

"undefined"

>>> typeof Math

"object"

>>> typeof String

"function"

Members of the Math Object

Property/Method	Description
Math.E Math.LN10 Math.LN2 Math.LOG2E Math.LOG10E Math.PI Math.SQRT1_2 Math.SQRT2	These are some useful math constants, all read-only. Here are their values: >>> Math.E 2.718281828459045 >>> Math.LN10 2.302585092994046 >>> Math.LN2 0.6931471805599453 >>> Math.LOG2E 1.4426950408889634 >>> Math.LOG10E 0.4342944819032518 >>> Math.PI 3.141592653589793 >>> Math.SQRT1_2 0.7071067811865476 >>> Math.SQRT2 1.4142135623730951
Math.acos(x) Math.asin(x) Math.atan(x) Math.atan2(y, x) Math.cos(x) Math.sin(x) Math.tan(x)	Trigonometric functions
Math.round(x) Math.floor(x) Math.ceil(x)	round() gives you the nearest integer, ceil() rounds up and floor() rounds down: >>> Math.round(5.5) 6 >>> Math.floor(5.5) 5 >>> Math.ceil(5.1) 6
Math.max(num1, num2, num3, ...) Math.min(num1, num2, num3, ...)	max() returns the largest and min() returns the smallest of the numbers passed to them as arguments. If at least one of the input parameters is NaN, the result is also NaN. >>> Math.max(2, 101, 4.5) 101 >>> Math.min(2, 101, 4.5) 2
Math.abs(x)	Absolute value. >>> Math.abs(-101) 101 >>> Math.abs(101) 101
Math.exp(x)	Exponential function: Math.E to the power of x
Math.log(x)	Natural logarithm of x.
Math.sqrt(x)	Square root of x . >>> Math.sqrt(9) 3 >>> Math.sqrt(2) === Math.SQRT2 true
Math.pow(x, y)	x to the power of y. >>> Math.pow(3, 2) 9
Math.random()	Random number between 0 and 1 (including 0). >>> Math.random() 0.8279076443185321