Sams Teach Yourself C in 21 Days

Answers 837

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4. The first line of a function definition must be the function header. It contains the
   function’s name, its return type, and its parameter list.


5. A function can return either one value or no values. The value can be of any of the
   C variable types. On Day 18, “Getting More from Functions,” you’ll see how to get
   more values back from a function.


6. A function that returns nothing should be type void.


7. A function definition is the complete function, including the header and all the
   function’s statements. The definition determines what actions take place when the
   function executes. The prototype is a single line, identical to the function header,
   but it ends with a semicolon. The prototype informs the compiler of the function’s
   name, return type, and parameter list.


8. A local variable is declared within a function.


9. Local variables are independent from other variables in the program.
   10.main()should be the first function in your listing.

Exercises

1.float do_it(char a, char b, char c)

Add a semicolon to the end, and you have the function prototype. As a function

header, it should be followed by the function’s statements enclosed in braces.

2.void print_a_number( int a_number )

This is a voidfunction. As in exercise 1, to create the prototype, add a semicolon

to the end. In an actual program, the header is followed by the function’s state-

ments.

3. a.int
   b.long


4. There are two problems. First, the print_msg()function is declared as a void;
   however, it returns a value. The returnstatement should be removed. The second
   problem is on the fifth line. The call to print_msg()passes a parameter (a string).
   The prototype states that this function has a voidparameter list and, therefore,
   shouldn’t be passed anything. The following is the corrected listing:
   #include <stdio.h>
   void print_msg (void);
   int main( void )
   {
   print_msg();
   return 0;
   }

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