Question 1 :
If the file to be included doesn't exist, the preprocessor flashes an error message.
True, the included file does not exist it will generate the error.
Question 2 :
Preprocessor directive #undef can be used only on a macro that has been #define earlier
True, #undef can be used only on a macro that has been #define earlier
Example: #define PI 3.14
We can undefine PI macro by #undef PI
Question 3 :
There exists a way to prevent the same file from getting #included twice in the same program.
True, We can prevent the same file from getting included again by using a preprocessor directive called #ifndef (short for "if not defined") to determine whether we've already defined a preprocessor symbol called XSTRING_H. If we have already defined this symbol, the compiler will ignore the rest of the file until it sees a #endif (which in this case is at the end of the file).
#define XSTRING_H defines the same preprocessor symbol,
Finally, the last line of the file, #endif
Question 4 :
A preprocessor directive is a message from programmer to the preprocessor.
True, the programmer tells the compiler to include the preprocessor when compiling.
Question 5 :
Macro calls and function calls work exactly similarly.
False, A macro just replaces each occurrence with the code assigned to it. e.g. SQUARE(3) with ((3)*(3)) in the program.
A function is compiled once and can be called from anywhere that has visibility to the funciton.