Visual Basic Data Types

Visual Basic has many different data types. We are interested in only a few for now.

• String variables are a nonnumeric data type that can be used to store text values up to 2 billion characters long. The maximum length will differ on individual machines because of available memory, overhead, and other programs.

Any character may be stored in a string variable.

• Short (int16) variables can be used to store a whole number between -32,786 and 32,767
• Integer (int32) varibles can be used to store a whole number between -2,147,483,648 and 2,147,483,647
• Long (int64) variables use 8 bytes and can store very large whole numbers.

Note: If you know that a variable will always store whole numbers (such as 12) rather than numbers with a fractional amount (such as 3.57), declare it as an Integer data type. Operations are faster with integers, and these types consume less memory than other data types.

• Single variables are used to store single-precision floating-point numbers. They can store numbers with fractional values.
• Double variables are used to double-precision floating-point numbers. They can store numbers that are very large, very small, or have many decimal positions.
• Decimal variables are also used to store numbers with fractional values. Because the value is stored differently in Decimal variables they are not as subject to rounding errors as Single an Double.

The highest positive values of the non-integral types are 7.9228162514264337593543950335E+28 for Decimal, 3.4028235E+38 for Single, and 1.79769313486231570E+308 for Double.

• Boolean variables are used as a flag or switch. The value of a Boolean variable is either True or False. Boolean variables are used to indicate the absence or presence of a certain condition. The properties AutoSize, Visible, and Enabled, MultiLine are all Boolean properties.