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Event Driven Programming

6.1 Structure
Some of the data types we have worked with so far are Double, Integer, String, and Boolean.
In previous versions of Visual Basic a Structure was called a user-defined type (UDT). Three pieces
of related information about colleges are “name,” “state,” and “year founded.” A Structure type
capable of holding this data is defined by the following block of statements located in the
Declarations section of the Code window.
College
Dim name As String
Dim state As String
Dim yearFounded As Integer
End
Each of the three subvariables of the Structure type is called a member. A Structure variable of
the type College is declared by a statement such as Dim college1 As College
Each member is accessed by giving the name of the Structure variable and the member, separated
by a period. For instance, the three members of the Structure variable college1 are accessed as
college1.name, college1.state, an college1.yearFounded. In general, a Structure type is defined by
a Structure block of the form
StructureType
Dim memberName1 As MemberType1
Dim membername2 As MemberType2
.
.
End
where StructureType is the name of the user-defined data type; memberName1,
memberName2,..., are the names of the members of the Structure; and MemberType1,
MemberType2,..., are the corresponding member types, such as String, Integer, Double, or
Boolean.
A Structure variable, structureVar, is declared to be of the user-defined type by a statement of
the form Dim structureVar As StructureType.

Subvariables of the Structure type is called a member.

1: The following program stores information about two colleges into Structure
variables of type College and uses the variables to determine which college
is older. Note: In the third line of the btnOlder_Click event procedure, all the
member values of college1 are assigned simultaneously to collegeOlder.

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