Using Caché Objects - InterSystems Documentation

Methods
where count and state are declared as %Integer and %String, respectively. By default, arguments
are of the %String data type, so that an argument of unspecified type is a %String. This is the
case for name in the above example. Generally it is a good idea to explicitly specify the data
type of of each method argument.
6.1.1 Specifying Default Values
To specify an argument's default value, set it equal to the desired value:
Method Test(flag As %Integer = 0)
{
}
When a method is invoked, it uses its default values (if specified) for any missing arguments.
6.1.2 Calling By Reference
By default, method arguments are passed by value. You can call an argument by reference
using the ByRef modifier:
/// Swap value of two integers
Method Swap(ByRef x As %Integer, ByRef y As %Integer)
{
Set temp = x
Set x = y
Set y = temp
}
You can also specify an argument whose value is returned by reference but has no incoming
value by using the Output modifier. This is equivalent to ByRef except that any incoming
argument values are ignored.
Method CreateObject(Output newobj As MyApp.MyClass) As %Status
{
Set newobj = ##class(MyApp.MyClass).%New()
Quit $$$OK
}
In Caché ObjectScript, when calling a method which has arguments that are passed by reference
(ByRef or Output), you must place a dot “.” before each of the arguments being called
by reference, such as:
Do obj.Swap(.arg1, .arg2)
You can pass both simple variables and OREFs (object references) by reference using this
syntax.
38 Using Caché Objects