Introduction to Parameters and Objects - Building Java Programs: A Back to Basics Approach - page 150

Table 3.1 Math Constants

Constant Description

base used in natural logarithms (2.71828...)

E

ratio of circumference of a circle to its diameter (3.14159 ...)

PI

Notice that we passed a value of type int to Math.sqrt , but the header says that
it expects a value of type double . Remember that if Java is expecting a double and
gets an int , it converts the int into a corresponding double .
The Math class also defines two frequently used constants: e and (see Table 3.1).

Following the Java convention, we use all uppercase letters for their names and refer
to them as Math.E and Math.PI .
Table 3.2 lists some of the most useful static methods from the Math class. You
can see a complete list of methods defined in the Math class by checking out the API

π

Table 3.2 Useful Static Methods in the Math Class

Method Description Example

absolute value Math.abs(-308) returns 308 abs

ceiling (rounds upward) Math.ceil(2.13) returns 3.0

ceil

cosine (radians) Math.cos(Math.PI) returns -1.0 cos

exponent base e Math.exp(1) returns

2.7182818284590455

exp

floor (rounds downward) Math.floor(2.93) returns 2.0

floor

logarithm base e Math.log(Math.E) returns 1.0 log

logarithm base 10 Math.log10(1000) returns 3.0

log10

maximum of two values Math.max(45, 207) returns 207 max

minimum of two values Math.min(3.8, 2.75) returns 2.75

min

power (general exponentiation) Math.pow(3, 4) returns 81.0 pow

random value Math.random() returns a random

double value k such that 0.0

random

k 1.0

round real number to nearest Math.round(2.718) returns 3

round

integer

sine (radians) Math.sin(0) returns 0.0

sin

square root Math.sqrt(2) returns

1.4142135623730951

sqrt

converts from radians to degrees toDegrees Math.toDegrees(Math.PI)

returns 180.0

converts from degrees to radians Math.toRadians(270.0) returns

4.71238898038469

toRadians