Javascript [Electronic resources] : The Definitive Guide (4th Edition)

David Flanagan

نسخه متنی -صفحه : 844/ 281
نمايش فراداده

Availability

JavaScript 1.0; JScript 1.0; ECMAScript v1

Synopsis

Math.constant Math.function( )

Constants

Math.E

The constant

e the base of the natural logarithms.

Math.LN10

The natural logarithm of 10.

Math.LN2

The natural logarithm of 2.

Math.LOG10E

The base-10 logarithm of

e

Math.LOG2E

The base-2 logarithm of

e

Math.PI

The constant .

Math.SQRT1_2

1 divided by the square root of 2.

Math.SQRT2

The square root of 2.

Static Functions

Math.abs( )

Computes an absolute value.

Math.acos( )

Computes an arc cosine.

Math.asin( )

Computes an arc sine.

Math.atan( )

Computes an arc tangent.

Math.atan2( )

Computes the angle from the X-axis to a point.

Math.ceil( )

Rounds a number up.

Math.cos( )

Computes a cosine.

Math.exp( )

Computes an exponent of

e

Math.floor( )

Rounds a number down.

Math.log( )

Computes a natural logarithm.

Math.max( )

Returns the larger of two numbers.

Math.min( )

Returns the smaller of two numbers.

Math.pow( )

Computes

xy

Math.random( )

Computes a random number.

Math.round( )

Rounds to the nearest integer.

Math.sin( )

Computes a sine.

Math.sqrt( )

Computes a square root.

Math.tan( )

Computes a tangent.

Description

Math is an object that defines properties that refer to useful mathematical functions and constants. These functions and constants are conveniently grouped by this Math object and are invoked with syntax like this:

y = Math.sin(x);
area = radius * radius * Math.PI; 

Math is not a class of objects like Date and String are. There is no Math( ) constructor, and functions like Math.sin( ) are simply functions, not methods that operate on an object.

See Also

Number