JavaScript Math Object

The JavaScript Math object provides a collections of mathematical constants and methods for performing such tasks as generating random numbers, rounding, obtaining values such as PI and performing calculations.

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JavaScript Math Object Methods

The following table lists the methods available with the Math object:

Method	Description
abs	Absolute value
sin, cos, tan	Standard trigonometric functions; argument in radians
acos, asin, atan, atan2	Inverse trigonometric functions; return values in radians
exp, log	Exponential and natural logarithm, base e
ceil	Returns least integer greater than or equal to argument
floor	Returns greatest integer less than or equal to argument
min, max	Returns greater or lesser (respectively) of two arguments
pow	Exponential; first argument is base, second is exponent
random	Returns a random number between 0 and 1.
round	Rounds argument to nearest integer
sqrt	Square root

JavaScript Math Object Properties

In addition the math object contains a number of properties for accessing mathematical constants:

Property	Description
E	Euler's constant
LN2	Natural log of 2
LN10	Natural log of 10
LOG2E	Log base -2 of E
LOG10E	Log base -10 of E
PI	Value of Pi
SQRT1_2	Square root of 0.5
SQRT2	Square root of 2

Using JavaScript Math Object and Properties

the first thing to be aware of with the Math object is that an instance of the object already exists. It is not necessary, therefore, to create a new instance using the new keyword. You can simply access the methods and properties by referencing Math.

The methods and properties of the JavaScript Math object can be accessed jsut as with any other objects (see JavaScript Object Basics for more information). For example we can obtain the value of Pi:

Math.Pi;

We can perform square root calculation:

Math.sqrt(3);
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== Generating Randon Numbers in JavaScript ==

The JavaScript Math object provides the ''random()'' method to generate randon numbers. When developing tyhe ''random()'' method the architects of JavaScript did not know what range you would the use for generation of the randon number. To address this they decided to generate a number between 0 and 1 and then leave you to mulitply it by factors of 10.

To obtain a random number between 0 and 10, for example:

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var randomNum = Math.random*10;