C++ Quiz 4/20/99                                                           

Part A: Mark your answers on the computer grade book program.

1. What is the value of the integer expression: 1 - 3 * 5 + 6 / 4 % 2

   (a)	0
   (b)	-8
   (c)	-13
   (d)	-15

   
   
2. If addition had higher precedence than multiplication, then the value of the expression

   1 + 2 * 3 + 4 * 5

   would be which of the following?
   

   (a)	65
   (b)	69
   (c)	105
   (d)	135

   
   
3. True or false: The expressions a + b % c and (a + b) % c are equivalent.
   
   
4. True or false: The expressions a - b + c and (a - b) + c are equivalent.
   
   
5. The value of the expression 19 / 8.0

   (a)	has type double and value 2.375
   (b)	has type double and value 2
   (c)	has type int and value 2
   (d)	has type int and value 2.375

    

7. By the rules of short-circuit evaluation, in the following expression,

p || (n < 3)

    for (i = 0; i < 12; i++)
        cout << i + 1 << endl;

    int num = 10;
    int sum;

Which of the following code segments correctly computes the sum of the first 10 multiples of 5 (i.e., 5, 10, ..., 50)?

sum = 5;
while (num > 1)
{
    sum += sum;
    num--;
}

sum = 0;
while (num >= 0)
{
    num--;
    sum += 5 * num;
}

sum = 5;
while (num > 0)
{
    sum += sum;
    num--;
}

sum = 0;
while (num > 0)
{
    sum += 5 * num;
    num--;
}

sum = 0;
while (num > 0)
{
    num--;
    sum += 5 * num;
}

10. True or False: When a function is called, the number of arguments should be the same as the number of parameters in the function's prototype.

11. True or False: A function prototype must include names and types for all parameters.

12. True or False: The definition of a function must appear in your program file before any calls to that function.

13. A function f which takes two integer parameters and does not return any value could have the function prototype:

(a)	f(int, int);
(b)	void f(int);
(c)	void f(int, int);
(d)	int f(void, void);

14. True or False: It would be legal to have these two function prototypes in the same program:

	double f(int);
	int f(int);

	double f(int, int);
	int f(int, double);

	void Myst(int a, int& b)
	{
		a *= b;
		b = 2 + a;
	}

	void Test()
	{
		int u = 2;
		int v = 3;
		Myst(u, v);
		cout << u << " " << v << endl;
	}

Part B:

1. Write down (line by line) the output of the following program:

   #include <iostream.h>
   
   int main()
   {
     int a, b;
   
     a = 6;
     b = a + 7;
     cout << "a = " << a << ", b = " << b << endl;
   
     a += b / 3;
     cout << "a = " << a << ", b = " << b << endl;
   
     a = b = 2 * a;
     cout << "a = " << a << ", b = " << b << endl;
   }
   

2. Write a program that inputs a list of integers, terminated by entering 0, then displays the number of even numbers included in the list.

3. Write a for loop to print out the squares of the first 8 odd numbers (that is, 1, 9, 25, 49, 81, 121, 169, 225). Your solution should use only one variable.

int deep(int, int);
int space(int);

int main()
{
    int a = 1, b = 2, c = 3;
    b = space(c);
    cout << "main: a = " << a << ", b = " << b << ", c = " << c << endl;
}

int deep(int x, int y)
{
    int z;
    z = x - y;
    cout << "deep: x = " << x << ", y = " << y << ", z = " << z << endl;
    return(z);
}

int space(int c)
{
    int a = 1, b;
    b = c * 2 + a;
    a = b + 5;
    c = deep(a, b);
    cout << "space: a = " << a << ", b = " << b << ", c = " << c << endl;
    return(b);
}

5. Write a function hundreds which, given an integer argument, returns the digit in the hundreds place. If the number is less than 100, it should return 0. So hundreds(1234) should return 2, and hundreds(1001) and hundreds(95) should both return 0.

6. Assume that you are designing a program in which you need a void function called readAndAverage that reads a given number of double values and returns their average. The number of values to process is read as user input into a variable in the main program. Write the function prototype (only) for readAndAverage, using call-by-value or call-by-reference parameters as appropriate.