KwickClips C++ · 43 sec · free
When is code kept or dropped?
Short answer. Before compiling.
What closes the block?
#endif.
Conditional compilation
| #ifdef DEBUG: keep if defined |
| #if MARKS >= 33: keep if true |
| #endif closes the block |
Remember
| Kept or dropped before compiling |
| Always close with #endif |
Can a line vanish before compiling? Yes. Directives decide. If def keeps code when a name is defined. Hash if keeps code when a condition is true. End if closes it. Remember this. Code is kept or dropped first. Close with end if.
This clip is from the full lesson: The C Preprocessor: Macros and Conditional Compilation — 7 minutes, with the tables, the quick answers and the whole lesson in text.
Useful for: CBSE Class 10 Information Technology (402), Programming All levels C, Programming All levels C
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