Updated Java tutorial with BigInteger and BigDecimal

This commit is contained in:
Robert Rose 2015-10-12 17:52:21 -04:00
parent 26696b764b
commit a504713d00

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@ -95,11 +95,13 @@ public class LearnJava {
// Note: Java has no unsigned types. // Note: Java has no unsigned types.
// Float - Single-precision 32-bit IEEE 754 Floating Point // Float - Single-precision 32-bit IEEE 754 Floating Point
// 2^-149 <= float <= (2-2^-23) * 2^127
float fooFloat = 234.5f; float fooFloat = 234.5f;
// f or F is used to denote that this variable value is of type float; // f or F is used to denote that this variable value is of type float;
// otherwise it is treated as double. // otherwise it is treated as double.
// Double - Double-precision 64-bit IEEE 754 Floating Point // Double - Double-precision 64-bit IEEE 754 Floating Point
// 2^-1074 <= x <= (2-2^-52) * 2^1023
double fooDouble = 123.4; double fooDouble = 123.4;
// Boolean - true & false // Boolean - true & false
@ -115,6 +117,34 @@ public class LearnJava {
final double E; final double E;
E = 2.71828; E = 2.71828;
// BigInteger - Immutable arbitrary-precision integers
//
// BigInteger is a data type that allows programmers to manipulate
// integers longer than 64-bits. Integers are stored as an array of
// of bytes and are manipulated using functions built into BigInteger
//
// BigInteger can be initialized using an array of bytes or a string.
BigInteger fooBigInteger = new BigDecimal(fooByteArray);
// BigDecimal - Immutable, arbitrary-precision signed decimal number
//
// A BigDecimal takes two parts: an arbitrary precision integer
// unscaled value and a 32-bit integer scale
//
// BigDecimal allows the programmer complete control over decimal
// rounding. It is recommended to use BigDecimal with currency values
// and where exact decimal percision is required.
//
// BigDecimal can be initialized with an int, long, double or String
// or by initializing the unscaled value (BigInteger) and scale (int).
BigDecimal fooBigDecimal = new BigDecimal(fooBigInteger, fooInt);
// Strings // Strings
String fooString = "My String Is Here!"; String fooString = "My String Is Here!";