CS 101-01 Quizzes

  1. Date: Feb. 11, 2013
     Question: Which of the following words are NOT java identifiers? Explain.
    Answer:
  2. Date: Feb. 18, 2013
     Question: What is the output of the following program segment? 
    	int x=5;
	float f = (float) 6.78;
	System.out.println("x is "+ x+"\n\t\b"+f+" meters");
	System.out.println("The results is shown above\ris reverse");

    Answer:     
    x is 5
6.78 meters
is reverse is shown above
    See the sample code.
  3. Date: Feb. 25, 2013
     Question: Write a complete java program that will read the number of students in three sections of CS 101 class separately and display the average number o stdents in a section.
    Answer:     
    /**
 * @(#)Q_01_3.java
 *
 * @author H. Altay Güvenir
 * @version 1.00 2013/2/25
 */
import java.util.Scanner;

public class Q_01_3 {
	public static void main (String[] args) {
		Scanner keyboard = new Scanner (System.in);

		int s1; // Number of students in Section 1
		System.out.print ("Enter the number of students in section 1: ");
		s1 = keyboard.nextInt(); // read s1 from the keyboad

		int s2; // Number of students in Section 2
		System.out.print ("Enter the number of students in section 2: ");
		s2 = keyboard.nextInt(); // read s2 from the keyboad

		int s3; // Number of students in Section 3
		System.out.print ("Enter the number of students in section 3: ");
		s3 = keyboard.nextInt(); // read s3 from the keyboad

		double average = (s1+s2+s3)/3.0; // compute the average
		System.out.println ("Average number of students in a section is "+ average);
	} // main
} // class Q_01_3
    See the sample code.
  4. Date: Mar. 6, 2013
     Question: Define shirt sizes as an enumerated type. Declare the shirt sizes of your three friends. Assign proper values to these variables. Display the values the values of these variables with appropriate information. Also display the ordinal values of these values.
    Answer:     
    /**
 * @(#)Q_01_4.java
 *
 * @author H. Altay Güvenir
 * @version 1.00 2013/3/6
 */

public class Q_01_4 {
	
	enum ShirtSize {extraSmall, small, medium, large, extraLarge, extraExtraLarge};
	
	public static void main (String[] args) {
		ShirtSize narinSize, jaleSize, tosunSize; // shirt sizes of three friends

		narinSize = ShirtSize.extraSmall; 	// Hale wares extra small size shirts
		jaleSize  = ShirtSize.small;		// Jale wares small size shirts
		tosunSize = ShirtSize.extraLarge;	// Tosun wares large size shirts

		System.out.println("Shirt size for Narin is "+ narinSize+".");
		System.out.println("Shirt size for Jale is " + jaleSize+".");
		System.out.println("Shirt size for Tosun is "+ tosunSize+".");

		// Displaying the ordinal values of the variables of ShirtSize type
		System.out.println ("Ordinal value of "+narinSize+" is "+narinSize.ordinal());
		System.out.println ("Ordinal value of "+jaleSize+" is "+jaleSize.ordinal());
		System.out.println ("Ordinal value of "+tosunSize+" is "+tosunSize.ordinal());		
	} // main
} // class Q_01_4
    See the sample code.
  5. Date: Apr. 3, 2013
     Question: What is the output of the following program? 
    public class Q_01_5 {
	
	public static void main(String[] args) {
		int x, y, z;
		x = 5;
		z = 0;
		while (x-- > 0) {
			y = x + 2;
			while (y > 0)
				  System.out.println(y--%2==0?z++:z--);	
		} // while	
		System.out.println(z);	
	} // main
}  // class Q_01_5

    Answer:     
    0
1
0
1
0
1
0
-1
0
-1
0
-1
0
-1
0
-1
-2
-1
-2
-1
-2
    See the sample code.
  6. Date: Apr. 10, 2013
     Question: Given the bottleList, which is an ArrayList of WaterBottle objects, write a program segment that prints the brandName of the WaterBottle object whose capacity is the minimum.
    Answer:     
    	WaterBottle minBottle = bottleList.get(0);
	float minCap = minBottle.getCapacity();
		
	// Using a for-each loop
	for (WaterBottle wb: bottleList)
		if (wb.getCapacity() < minCap) {
			minBottle = wb;
			minCap = minBottle.getCapacity();
		}
	System.out.println(minBottle.getBrandName());
    See the sample code.
  7. Date: Apr. 17, 2013
     Question: Write a method to compute ex using its Talor series definition as
    .
    Answer:     
    	private static int factorial (int n) {
		int result = 1;
		for (int i=2; i<=n; i++)
			result *= i;
		return result;
	} // factorial
	
	public static double e (double x) {
		double sum =0;
		for (int k=0; k<20; k++)
			sum += Math.pow(x, k) / factorial(k);
		return sum;
	} // e
    See the sample code.
  8. Date: May 06, 2013
     Question: Write a method, called find, which takes an int array, called ar, and another int value, called key. It returns the index of key in ar. If the key does not exist in ar, it returns -1.
    Answer:     
    	public static int find (int[] ar, int key) {
		for (int i=0; i < ar.length; i++)
			if ( key== ar[i] )
				return i;
		return -1;
	} // find
    See the sample code.
  9. Date: May 08, 2013
     Question: Write a method, that takes a double[][] as its parameter and returns the sum of values in the array.
    Answer:     
    	public static double sum2D (double[][] da) {
		double sum = 0;
		for (int r=0; r < da.length; r++)
			for (int c=0; c<da[r].length; c++)
				sum += da[r][c];
		return sum;
	} // sum2D
    See the sample code.