Advanced Coding (from Fraktal SAS Programming)
While the crude approach to MACRO programming is 1st choice for any ad-hoc implementation it will quite unlikely result in a piece of software that will survive in a quality controlled environment. Moreover, when used as component in a modularized system it will not produce predictable results and very likely mess things up at run-time.
The key reason is, that SAS languages – like other programming languages – do use variable properties, but without forcing the programmer to deliver this information by declaring everything forehand in a header section or similar place.
SAS code is executed regardless whether explicit declaration is found or not. When none is found, SAS applies built-in rules to perform automatic declaration on which it then operates. Properties given that way might not conform with programmers’ expectations or the system’s design requirements.