Visual Basic 2005 for Programmers: Deitel Developer Series, Second Edition

4.6. Value Types and Reference Types

Data types in Visual Basic are divided into two categories—value types and reference types. A variable of a value type (such as Integer) simply contains a value of that type. For example, Fig. 4.10 shows an Integer variable named count that contains the value 7.

Figure 4.10. Value type variable.

By contrast, a variable of a reference type (sometimes called a reference) contains the memory address where the data referred to by that variable is stored. Such a variable is said to refer to an object in the program. Line 8 of Fig. 4.8 creates a GradeBook object, places it in memory and stores the object’s memory ...