Vision VTB-101 Guia do Utilizador descarregar pdf (Página 23)

VTB USER GUIDE

It's also possible to declare pointers to data STRUCTURES.

Example

This structure is been declared

Used variables:

pointer as *Example ‘ pointer to structure Example

struct as Example ‘ struct is a structure type variable

pointer=struct() ‘ pointer points to structure

pointer->Var1=300 ‘ writing of both fields of structure by pointer

pointer->Var2=200

As we have seen, to use pointer with the structures we need the token →

WARNING: VTB doesn't make any control on the index of pointer therefore with pointers it's possible to write anywhere

in memory with consequent risks to crash the system.

Example:

pnt as *long

value as long

pnt=value()

pnt[10]=1234

The inscrution punt[10] = 1234 doesn't generate any compiling or run-time error, but it can cause unexpected

operations. The correct use is:

pnt[0]=1234

To get the address of a function to assign to a variable we have to refer at the function simply with its name (without

brackets):

Example

VarPnt=MyFunction

Where MyFunction is a declared function

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Vision VTB-101 Guia do Utilizador Página 23