User manual

mikroBasic PRO for dsPIC30/33 and PIC24
MikroElektronika
213
Structures
A structure represents a heterogeneous set of elements. Each element is called a member; the declaration of a structure
type species a name and type for each member. The syntax of a structure type declaration is
structure structname
dim member1 as type1
‘...
dim membern as typen
end structure
where structname is a valid identier, each type denotes a type, and each member is a valid identier. The scope
of a member identier is limited to the structure in which it occurs, so you don’t have to worry about naming conicts
between member identiers and other variables.
For example, the following declaration creates a structure type called Dot:
structure Dot
dim x as oat
dim y as oat
end structure
Each Dot contains two members: x and y coordinates; memory is allocated when you instantiate the structure, like this:
dim m, n as Dot
This variable declaration creates two instances of Dot, called m and n.
A member can be of the previously dened structure type. For example:
‘ Structure dening a circle:
structure Circle
dim radius as oat
dim center as Dot
end structure
Structure Member Access
You can access the members of a structure by means of dot (.) as a direct member selector. If we had declared the
variables circle1 and circle2 of the previously dened type Circle:
dim circle1, circle2 as Circle
we could access their individual members like this:
circle1.radius = 3.7
circle1.center.x = 0
circle1.center.y = 0
You can also commit assignments between complex variables, if they are of the same type:
circle2 = circle1 ‘ This will copy values of all members