21. In C, how do you use the #ifndef directive to conditionally include code if a macro is not defined? A. #ifndef MACRO B. #ifndef(MACRO) C. #ifndef:MACRO D. #ifndef: MACRO Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
22. What does the #pragma once directive do in C preprocessing? A. Prevents multiple inclusion of header files B. Defines a macro C. Checks for syntax errors D. Excludes code Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
23. In C, what is the purpose of the #ifdef directive? A. Checks if a macro is defined B. Checks if a macro is not defined C. Defines a macro D. Includes a header file Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
24. What is the purpose of the #pragma warning directive in C preprocessing? A. Generates a warning message B. Defines a macro C. Checks for syntax errors D. Excludes code Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
25. In C preprocessing, what is the purpose of the #elifdef directive? A. Checks if a macro is defined B. Checks if a macro is not defined C. Provides an alternative condition D. Defines a macro Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board
26. What is the result of the #pragma message directive in C preprocessing? A. Includes a message in the code B. Defines a macro C. Checks for syntax errors D. Excludes code Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
27. What is the purpose of the #undef directive in C preprocessing? A. Undefines a macro B. Defines a macro C. Checks for syntax errors D. Excludes code Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
28. In C preprocessing, what is the purpose of the #elifndef directive? A. Checks if a macro is defined B. Checks if a macro is not defined C. Provides an alternative condition D. Defines a macro Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B No explanation is given for this question Let's Discuss on Board
29. What is the result of the #pragma warning directive in C preprocessing? A. Generates a warning message B. Defines a macro C. Checks for syntax errors D. Excludes code Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
30. In C, what is the purpose of the #line directive? A. Specifies the line number and filename in the source file B. Defines a macro C. Checks for syntax errors D. Excludes code Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board