Visual Basic 2012 Programmer's Reference

DATA TYPES

The smallest piece of data a computer can handle is a bit, a single value that can be either 0 or 1. Eight bits are grouped into a byte. Computers typically measure disk space and memory space in kilobytes (1,024 bytes), megabytes (1,024 kilobytes), and gigabytes (1,024 megabytes).

Multiple bytes are grouped into words that may contain 2, 4, or more bytes depending on the computer hardware. Most computers these days use 4-byte (32-bit) words, although 8-byte (64-bit) computers are becoming more common.

Visual Basic also groups bytes in different ways to form data types with a higher logical meaning. For example, it uses 4 bytes to make an integer, a numeric data type that can hold values between ’2,147,483,648 and 2,147,483,647.

The following table summarizes Visual Basic’s elementary data types.

TYPE	SIZE	VALUES
Boolean	2 bytes	True or False
Byte	1 byte	0 to 255 (unsigned byte)
SByte	1 byte	’128 to 127 (signed byte)
Char	2 bytes	0 to 65,535 (unsigned character)
Short	2 bytes	’32,768 to 32,767
UShort	2 bytes	0 through 65,535 (unsigned short)
Integer	4 bytes	’2,147,483,648 to 2,147,483,647
UInteger	4 bytes	0 through 4,294,967,295 (unsigned integer)
Long	8 bytes	’9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
ULong	8 bytes	0 through 18,446,744,073,709,551,615 (unsigned long)
Decimal	16 bytes	0 to +/’79,228,162,514,264,337,593,543,950,335 with no decimal point; 0 to +/’7.9228162514264337593543950335 with 28 places to the right of the decimal ...