Java Reference
In-Depth Information
C H A P T E R 4
Touring Language APIs
Java's standard class library provides various language-oriented APIs. Most of these
APIs reside in the
java.lang
package and its subpackages, although a few APIs
Math
and
StrictMath
,
Package
, Primitive Type Wrapper Class, Reference, Re-
flection,
String
,
StringBuffer
and
StringBuilder
,
System
, and Threading
APIs. This chapter then introduces you to
java.math
's
BigDecimal
and
BigIn-
teger
APIs.
Math and StrictMath
The
java.lang.Math
class declares
double
constants
E
and
PI
that represent the
natural logarithm base value (2.71828...) and the ratio of a circle's circumference to its
diameter(3.14159...).
E
isinitializedto
2.718281828459045
and
PI
isinitializedto
3.141592653589793
.
Math
alsodeclaresassortedclassmethodstoperformvarious
math operations.
Table 4-1
describes many of these methods.