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 ... |
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