Constants as Function Arguments

Passing a constant as a function argument, such as a STRING in quotes, means the argument is read only and cannot be assigned a new value. So if you define a function:

define function !!ChangeString( !Argument is STRING)

 !Argument = 'New Value'

endfunction

The following will change the value of !S:

!S = ‘Old Value’

!!ChangeString ( !S )

However, the following will result in a PML error message because the value passed to the function as an argument is a CONSTANT STRING value which cannot be modified.