Referencia de JavaScript 1.5:Objetos globales:Math
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[editar] Summary
Core Object
A built-in object that has properties and methods for mathematical constants and functions. For example, the Math object's PI property has the value of pi.
[editar] Created by
The Math object is a top-level, predefined JavaScript object. You can automatically access it without using a constructor or calling a method.
[editar] Description
All properties and methods of Math are static. You refer to the constant pi as Math.PI and you call the sine function as Math.sin(x), where x is the method's argument. Constants are defined with the full precision of real numbers in JavaScript.
It is often convenient to use the with statement when a section of code uses several Math constants and methods, so you don't have to type "Math" repeatedly. For example,
with (Math) {
a = PI * r*r
y = r*sin(theta)
x = r*cos(theta)
}
[editar] Properties
E: Euler's constant and the base of natural logarithms, approximately 2.718.
LN2: Natural logarithm of 2, approximately 0.693.
LN10: Natural logarithm of 10, approximately 2.302.
LOG2E: Base 2 logarithm of E, approximately 1.442.
LOG10E: Base 10 logarithm of E, approximately 0.434.
PI: Ratio of the circumference of a circle to its diameter, approximately 3.14159.
SQRT1_2: Square root of 1/2; equivalently, 1 over the square root of 2, approximately 0.707.
SQRT2: Square root of 2, approximately 1.414.
[editar] Methods
abs: Returns the absolute value of a number.
acos: Returns the arccosine (in radians) of a number.
asin: Returns the arcsine (in radians) of a number.
atan: Returns the arctangent (in radians) of a number.
atan2: Returns the arctangent of the quotient of its arguments.
ceil: Returns the smallest integer greater than or equal to a number.
cos: Returns the cosine of a number.
exp: Returns Enumber, where number is the argument, and E is Euler's constant, the base of the natural logarithms.
floor: Returns the largest integer less than or equal to a number.
log: Returns the natural logarithm (base E) of a number.
max: Returns the largest of zero or more numbers.
min: Returns the smallest of zero or more numbers.
pow: Returns base to the exponent power, that is, base exponent.
random: Returns a pseudo-random number between 0 and 1.
round: Returns the value of a number rounded to the nearest integer.
sin: Returns the sine of a number.
sqrt: Returns the square root of a number.
tan: Returns the tangent of a number.