Using Caché Objects - InterSystems Documentation

Using Objects with Caché ObjectScript
10.1.1 About Return Values
Some methods return a value when executed; others do not. If a method has a return value
and your application does not need it, you can invoke it using the syntax for methods that do
not return a value. To invoke a method without checking its return value, use the Do command;
to invoke a method and check use the Set command. Examples of invoking instance methods
each way appear in the section Executing Instance Methods; examples of invoking class
methods each way appear in the section Executing Class Methods.
10.1.2 Executing Instance Methods
To execute a instance method, you must first create (or open from the database) an instance
of an object.
To execute an instance method, use syntax similar to either of the following lines of code:
Do oref.MethodName(arglist)
Set value = oref.MethodName(arglist)
where oref is a reference to the relevant object that is already in memory (see the section
“Referring to an Object—OREFs and OIDs” in the chapter on the Caché object model for
more information on OREFs), MethodName is the name of the method to execute, and arglist
is the list of arguments passed to the method. value, in the second line of code, is a local
variable that receives the return value of the method.
For example, to execute the Admit method of a Patient object use the following code:
Do pat.Admit()
where pat is the OREF of the desired Patient object.
Similarly, to execute the SearchMedicalHistory method of a Patient object use the following
code:
Set result = pat.SearchMedicalHistory("MUMPS")
where pat is the OREF of the desired Patient object and result holds the value returned by
SearchMedicalHistory.
68 Using Caché Objects