Advanced Coding (from Fraktal SAS Programming): Unterschied zwischen den Versionen
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− | While the crude approach to MACRO programming is 1st choice for any ad-hoc implementation it will | + | 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. |
'''Why?''' | '''Why?''' |
Aktuelle Version vom 9. Mai 2014, 10:16 Uhr
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.
Why?
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.
That’s why!