Using Numbered Argument Variables

In a macro definition, argument variables can be referenced by the order in which they appear in the macro signature. Consider the following example macro signature with three argument variables:

SUM3(single, single, group)

To use the input from this function in the macro definition, you reference the arguments using the argument variables @@1 for the first input parameter, @@2 for the second input parameter, and @@3 for the third input parameter. Thus, using the macro in the preceding example and providing the following input,

SUM3("New York", "New Jersey", @CHILDREN(Products));

results in the macro variables being set to the following values:

@@1 = "New York"@@2 = "New Jersey"@@3 = @CHILDREN(Products)

Use of the optional argument in the macro signature has no effect on which macro variable represents which incoming argument; for example, the input,

Macro signature: SUM3(single, optional, group)
Macro input: SUM3("New York", , @CHILDREN(Products));

results in the macro variables being set to the following values:

@@1 = "New York"@@2 = @_NULL@@3 = @CHILDREN(Products)

Using Argument Variable Shortcuts

You can represent sets of arguments with the variable shortcuts @@S and @@SHx. These shortcuts enable you to specify a set of arguments with one variable, rather than listing a set of numbered variables. Using input from the preceding example, the @@S variable would be set to the following value:

@@S = "New York", @_NULL, @CHILDREN(Products)

Argument variables and shortcuts for custom-defined macros can be used in any order within a macro definition and can be repeated in a macro.