Questions 3

1. What is the option that instructs the gcc compiler to print out all warnings?
   Hints:
   GCC: run the command gcc --help=warnings | grep -i 'enable.*warning'.
   Clang: run the command clang --help | grep -i 'enable.*warning' and try to figure out.
2. Name the comparison operators in C.
3. Rewrite this piece of code, (a>b?a:b), using the if statement.
4. If you use mathematical functions from complex.h, do you need to link your program with -lm option?
   Hint: man complex|grep '\-lm'.
5. What will the following piece of code print?

   int i=1; printf("%i\n",i); printf("%i\n",i++); printf("%i\n",++i);
   

   Explain.
   How about

   int i=1; printf("%i %i %i\n",i,i++,++i);
   

   Hint: compile with -Wall.
6. Rewrite the loop while(condition)body using the for loop.
7. Rewrite the loop for(init;cond;inc)body using the while loop.
8. Rewrite the loop do body while(condition); using the for loop.
9. Is this a valid C-code?

   if(0) printf("0 is true\n");
   else  printf("0 is false\n");
   if(7) printf("7 is true\n");
   else  printf("7 is false\n");
   

   Hint: Wikipedia → C syntax → Selection statements.
10. Does C have a boolean type (that is, a type having one of the two values, "true" or "false") type?
    Hint: Wikipedia → Boolean data type →C.