programming-for-dummies

544
Declaring Variables
Declaring integer data types
Whole numbers represent integers, such as –9, 62, or 10. A whole number
can be positive or negative. The most common integer data type is int and
is used as follows:
int variablename;
Besides integer values, Java also offers a variety of other integer data types
that can hold a different range of values, as shown in Table 2-1.
Table 2-1 Typical Storage and Range Limitations of Java Integer Data Types
Data Type Number of Bytes Range
byte 1 –128 to 127
short 2 –32,768 to 32,767
int 4 –2,147,483,648 to 2,147,483,647
long 8 –9,223,372,036,854,775,808 to
9,223,372,036,854,775,807
C# also offers a variety of different integer data types, which can be signed
(positive and negative values) or unsigned (only positive values), as shown
in Table 2-2. To declare a signed or unsigned variable, use the signed (or
unsigned) keyword, such as
signed int profit;
unsigned short pets_owned;
Table 2-2 Typical Storage and Range Limitations of C# Integer Data Types
Data Type Number of Bytes Range
byte 1 Signed: –128 to 127
Unsigned: 0 to 255
short 2 Signed: –32,768 to 32,767
Unsigned: 0 to 65,535
int 4 Signed: –2,147,483,648 to
2,147,483,647
Unsigned: 0 to 4,294,967,295
long 8 Signed: –9,223,372,036,854,775,808 to
9,223,372,036,854,775,807
Unsigned: 0 to 1.8x1019