3.12. Chapter Review Questions¶

1. Write the function definition heading for a static function called Q1 which has two int parameters, x and y, and returns a double.

2. The function above must have what kind of a statement in its body?

3. Each of these lines has a call to the function above, Q1. Which are legal? Explain:

   double d = Q1(2, 5);
   
   int x = Q1(2, 5);
   
   double y = Q1(2) + 5.5;
   
   Console.WriteLine(Q1("2", "5"));
   
   Console.WriteLine(Q1(2.5, 5.5));
   
   Q1(10, 20);
   

4. Suppose Q1 does nothing except produce the value to return, like most functions returning a double. Which line in the previous problem is legal, but has no effect?

5. Write the function definition heading for a static function called Q4 which has one string parameter, s, and returns nothing.

6. Which of these lines with a call to the function above, Q4, is legal? Explain:

   Q4("hi");
   
   string t = Q4("hi");
   
   Console.WriteLine(Q4("hi"));
   
   Q4("hi" + "ho");
   
   Q4("hi", "ho");
   
   Q4(2);
   

7. Can you have more than one function/method in the same class definition with the same name?

8. What is a function/method signature? Can you have more than one function/method declared in the same class definition with the same signature?

9. In each part, is this a legal program? If so, what is printed? If not, why not?

   Each version uses the same code, except for different versions of Main. Here is the common code with the body of Main omitted:

   using System;
   class Local1
   {
      static int Q(int a)  // 1
      {                    // 2
         int x = 3;        // 3
         x = x + a;        // 4
         return x;         // 5
      }                    // 6
   
      static void Main()
      {
         // see each version
      }
   }
   

   1. Insert:

      static void Main()
      {
         Q(5);
         Console.WriteLine(x);
      }
      

   2. Insert instead:

      static void Main()
      {
         int x= 1;
         Q(5);
         Console.WriteLine(x);
      }
      

   3. Insert instead:

      static void Main()                   // 7
      {                                    // 8
         int x = 1, y = 2;                 // 9
         y = Q(5);                         // 10
         Console.WriteLine(x + " " + y);   // 11
      }                                    // 12
      

10. In the previous problem consider the common code with part c. Note the line numbers as comments.

    1. In what line(s) is Q being defined?
    2. In what line(s) is Q called?
    3. What is the return type of Q?
    4. What is a formal parameter to Q?
    5. What is used as an actual parameter to Q?
    6. What is the scope of the x in line 3?
    7. What is the scope of the x in line 9?