Variables and Data Types

A variable can be thought of as a memory location that can hold values of a specific type. The value in a variable may change during the life of the program—hence the name variable.

In VBA, each variable has a specific data type, which indicates which type of data it may hold. For instance, a variable that holds text strings has a String data type and is called a string variable. A variable that holds integers (whole numbers) has an Integer data type and is called an integer variable. For reference, Table 5-1 shows the complete set of VBA data types, along with the amount of memory that they consume and their range of values. We will discuss a few of the more commonly used data types in a moment.

Table 5-1. VBA Data Types

Type

Size in Memory

Range of Values

Byte

1 byte

0 to 255

Boolean

2 bytes

True or False

Integer

2 bytes

-32,768 to 32,767

Long (long integer)

4 bytes

-2,147,483,648 to 2,147,483,647

Single(single-precision real)

4 bytes

Approximately -3.4E38 to 3.4E38

Double(double-precision real)

8 bytes

Approximately -1.8E308 to 4.9E324

Currency(scaled integer)

8 bytes

Approximately -922,337,203,685,477.5808 to 922,337,203,685,477.5807

Date

8 bytes

1/1/100 to 12/31/9999

Object

4 bytes

Any Object reference.

String

Variable length:10 bytes + string length;Fixed length: string length

Variable length: <= about 2 billion (65,400 for Win 3.1) Fixed length: up to 65,400

Variant

16 bytes for numbers22 bytes + string length

Number: same as DoubleString: same as String

User-defined

Varies

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