perlperl
asked on
if def in c++
I have the noticed the following in code path
How can we set the variable SOME, is this something set using environment variable from the bash shell before executing the executable?
#if SOME == 1
// Do someting
#else
// Do something
#endifHow can we set the variable SOME, is this something set using environment variable from the bash shell before executing the executable?
ASKER CERTIFIED SOLUTION
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Just wanted to add (please do not award me any points, as you have already got your answer). The very same "variable" can be defined as a #define macro:
#define SOME 1
#if SOME == 1
// Do someting
#else
// Do something
#endif
Adding to the above comment,
In comanddline, we can only define a macro which helps for #ifdef/#ifndef ..etc. But for #if we have to specify a value to make it scence.
Ex:
#define SOME 1
......
......
#if SOME == 1
// Do someting===============>Th
#else
// Do something
#endif
##########################
#if is simillar to if-else stateent but difference is, if-else is taking the value from variable and that variable needs to be defined. But in #if, it takes the value defined by #define
In comanddline, we can only define a macro which helps for #ifdef/#ifndef ..etc. But for #if we have to specify a value to make it scence.
Ex:
#define SOME 1
......
......
#if SOME == 1
// Do someting===============>Th
#else
// Do something
#endif
##########################
#if is simillar to if-else stateent but difference is, if-else is taking the value from variable and that variable needs to be defined. But in #if, it takes the value defined by #define
ASKER
Thanks a lot everyone for comments.
ASKER
Thanks a lot!!