Computer Science 2610
Fall 2000
Practice questions for quiz 1

  1. Write a clearly legible T to the left of each of the following statements that is true and a clearly legible F to the left of each that is false.
    1. A function contract usually cannot be written until after the function is written.
    2. A function typically is given its data through its parameters.
    3. In order for a function to get any data to work on, it must include a "cin" line.
    4. The data type of real numbers is called real in C++.
    5. C++ uses 0 to mean "false" and 1 to mean "true".
    6. C++ is a professional software development language.
    7. The word if in C++ is usually used to start a loop.

  2. Function f2 is shown below, with part of its definition not shown, and replaced by three dots. There are no breaks in the part that is not shown, and nothing is printed there. (You have not seen breaks yet.) It is known that f2 prints something when it runs. What does it print?
    1. 24
    2. 25
    3. 26
    4. It is impossible to say without more information. 
          void f2()
      {
        int i = 100;
        while(i != 25) {
          ...
          i = i + 1;
        }
        cout << i;    
      }

  3. The following loop sets variable m to
    1. 1 + ... + 9
    2. 1 + ... + 10
    3. 1 + ... + 11
    4. 1 + ... + 12 
         int m,n;
     n = 0;
     m = 0;
     while(n < 10) {
      n++;
      m = m + n;
     }

  4. The following sets variable x to
    1. 2
    2. 3
    3. 4
    4. 5 
        int x,y,z;
    y = 4;
    z = y - 1;
    if(y > z || z < 0) x = z - 1;
    else x = z + 1;

  5. What is printed by the following C++ function when it is run? Be careful to note that all of the variables hold integers. 
           void four()
       {
         int x,y,z,w,b;
         x = 45;
         y = 2 * x + x * 3;
         z = x / 2;
         w = x % 2;
         b = x < y;
         cout << "x = " << x << " y = " << y << " z = " << z
		   << " w = " << w << " b = " << b << endl;
       }

    Answer: ________________________________________________________

  6. The geometric mean of two numbers x and y is the square root of the product of x and y. Write a C++ function called geometricMean that returns the geometric mean of its two parameters. 
                double geometricMean(double x, double y)

  7. Using function geometricMean from the previous exercise, write a program fragment that sets variable z to the geometric mean of variable r and twice variable s.

  8. Function f is defined as follows. 
         int f(int x)
     {
       int k = 1;
       while(k <= x) {
         k = k + k;
       }
       return k;
     }
    What are f(3) and f(f(3))? 
       f(3)     = _________


   f(f(3)) = _________