Apple Certification Exam 9L0-509

It's generally a good idea to use extra parentheses when using complex macros. Notice that in the above 9L0-509 example, the variable "x" is always within its own set of parentheses. This way, it will be evaluated in whole, before being compared to 0 or multiplied by -1. Also, the entire macro is surrounded by parentheses, to prevent it from being contaminated by other code. If you'9L0-402 dumps re not careful, you run the risk of having the compiler misinterpret your code.

Macros replace each occurrence of the macro parameter used in the text with the literal contents of the macro parameter without any validation checking. Badly written macros 9L0-509 can result in code which won't compile or create hard to discover bugs. Because of side-effects it is considered a very bad idea to use macro functions as described above. However as with any rule, there may be cases where macros are the most efficient means to accomplish a particular goal.
If ABSOLUTE_VALUE() was a real function 'z' would now have the value of '-9', but because it was an argument in a macro z++ was expanded 3 times (in this case) and thus (in this Testking 9L0-402 situation) executed twice, setting z to -8, and y to 9. In similar cases it is very easy to write code which has "undefined behavior", meaning that what it does is completely unpredictable in the eyes of the C++ Standard.