1. What will happen when you attempt to compile and run the following code?

public class Car {
	public static int i = 99;

	public static void main(String argv[]) {
		Car h = new Car();
		h.drive();
	}

	public void drive() {
		i = 10;
		int i = 20;
		System.out.println(this.i);

	}
}

a

Compile time error, variable i is used before it is created.

b

Compilation and output of 20

c

Compile time error

d

Compilation and output of 10

2. What will happen when you attempt to compile and run the following code?

public class Tab {

	public static void main(String argv[]) {
		new Tab().go();
	}

	public static void go() {
		hoe(new String("beans"));
	}

	protected void hoe(String s) {
		System.out.println(s);
	}
}

a

Compile time error, a constructor may not be marked as private

b

Compile time error, the code in the main method is faulty

c

Compile time error caused by a problem in the go method.

d

Compilation and output of "beans"

3. What will happen when you attempt to compile and run the following code?

import static java.lang.System.out;

public class Math {
	public static void main(String argv[]) {
		out.print(3 + 2 * 2);
		out.print(3 + (2 * 2));
		out.print(8 / 4 + 3);
		out.print(8 / (5 + 4));
		int i = 1;
		out.println(i++ * 6);

	}
}

a

Compile time error, out can not be resolved

b

1075012

c

77506

d

775012

4. What will happen when you attempt to compile and run the following code?

import java.util.Collections;
import java.util.Vector;

public class VectorSort{
    public static void main(String argv[]){
        new VectorSort();
   }
    VectorSort(){
        Vector<String> child = new Vector<String>();
        child.add("hans");
        child.add("marry");
        child.add("ben");
        Collections.sort(child);
        for(String element : child){
            System.out.print(element);
        }
    }
}

a

Compilation error, Vector class is not genericized

b

Compilation error, the for loop structure needs to cast each element of the Vector array to a String

c

Runtime error, the Collections.sort method can only sort objects of type List

d

Compilation and output of benhansmarry

5. What will happen when you attempt to compile and run the following code?

import java.util.ArrayList;
import java.util.Collections;

public class NameSort {
	public static void main(String argv[]) {
		new NameSort();
	}

	NameSort() {
		ArrayList al = new ArrayList();
		al.add("Robert");
		al.add("Michiel");
		al.add("Alex");
		Collections.sort(al);
		for (al :String element ) {
			System.out.print(element);
		}
	}
}

a

Compilation and output of AlexMichielRobert

b

Compilation and output of RobertMichielAlex

c

Compilation error because al is not type safe ArrayList

d

Compilation error, incorrect for loop structure

6. What must be inserted at '//insert code here' to produce output 950 116 ?

enum Engine {
	VW_TDI(90),
	// insert code here
	PEUGEOT_HDI(106);

	Engine(int power) {
		this.power = power;
		this.weight = power * 10;
	}

	int power;
	int weight;
	int getWeight() {	return weight;}
	void setWeight(int w) {		weight = w;	}
}

class EnginesTest {
	public static void main(String[] hay) {
		Engine h = Engine.ALFAROME_JTD;
		System.out.println(h.getWeight() + " " + h.power);
	}
}

a

ALFAROME_JTD(116) { weight = 950; },

b

ALFAROME_JTD(116) { setWeight( 950) ; },

c

ALFAROME_JTD(116) { public int getWeight() { return 950; } },

d

None

e

This will not compile

7. What will happen when you attempt to compile and run the following code?

public class Unbox {
	public static void main(String[] args) {
		int i = 2;
		new Unbox().doSomthing(i);
	}

	public void doSomthing(Double d) {
		System.out.println(d + 2);
	}

	public void doSomthing(double d) {
		System.out.println(d + 6);
	}

	public void doSomthing(Integer i) {
		System.out.println(i + 4);
	}
}

a

Compile and output 8.0

b

Compile and output 4.0

c

Compile and output 6

d

Compile and output 6.0

e

This will not compile, becouse of ambiguous method reference to doSomthing...

8. What will happen when you attempt to compile and run the following code?

public class Bird {

	public static void main(String[] args) {
		Bird rap = new Raptor();
		rap.doSomething(1);
		rap.doSomething(1,2);
	}

	public void doSomething(int i, int ...args) {
		System.out.print("Hallo ");
	}

	public void doSomething(double d, int i) {
		System.out.print("Ola");
	}	
}

class Raptor extends Bird {
	public void doSomething(int n){
		System.out.print("Ciao");
	}
}

a

Compile and output CiaoHallo

b

Compile and output CiaoOla

c

Compile and output HalloHallo

d

Compile and output HalloOla

e

This will not compile, becouse of ambiguous method referenc to doSomthing...

9. What is result when we run this code?

class Animal {
	  int doIt(Long i, Long z) { return 5; }
	  int doIt(int... i) { return 4; }
	  int doIt(Integer i, Integer z) { return 7; }
	  int doIt(Number i, Number z) { return 8; }

	  public static void main(String[] args) {
	    new Animal().go();
	  }
	  void go() {
	    short sh = 7;  
	    System.out.print(doIt(sh,sh));  
	    System.out.print(doIt(7,7));
	  }
}

a

Compile and output 87

b

Compile and output 44

c

Compile and output 54

d

Compile and output 84

e

Compile and output 74

10. What is the result of this code?

List <String> l1 = new ArrayList<String>();
List<Integer> l2 = new ArrayList<Integer>();
System.out.println(l1.getClass() == l2.getClass());

a

Compile and output false

b

Compile and output true

c

Compile errors

11. What will happen when you attempt to compile and run the following code?

1		ArrayList al = new ArrayList();
2		al.add(new Integer(2));
3		al.add(123);
4		Collections.sort(al);
5		for (Integer element :  al) {
6			System.out.print(element);
7		}

a

Compile and output 2123

b

Compile and output 1232

c

Compile errors on line 3 int is not appropriate type for ArrayList<Integer>

d

Compile errors on line 5 Type mismatch cannot convert from element type Object to Integer

12. What will happen when you attempt to compile and run the following code?(Because of problems during last deployment, this quest had wrong answer in exam results. We apologize for this.)

enum Operation {PLUS {}, MINUS {}, TIMES {}, DIVIDE {}}

public static void main(String args[]){
	System.out.print(Operation.PLUS.getClass() == Operation.MINUS.getClass());
	System.out.println(Operation.PLUS.getClass().equals(Operation.MINUS.getClass()));
}

a

Compile and output truefalse

b

Compile and output falsefalse

c

Compile and output truetrue

d

Compile and output falsetrue

13. What will happen when you attempt to compile and run the following code?

// given enum Operation
public enum Operation {

	PLUS {double eval(double x, double y) {return x+y;}},
	MINUS {double eval(double x, double y) {return x-y;}},
	TIMES {double eval(double x, double y) {return x*y;}},
	DIVIDE{double eval(double x, double y) {return x/y;}};
	
	// Do arithmetic op reattachmentsented by this constant
	abstract double eval(double x, double y);
}
// and a Test class

import static Operation.*;
public class Test {
	public static void main(String args[]){
		System.out.println(PLUS.eval(1.0, 2.0));
	}
}

a

Compile and output 3

b

Compile and output 3.0

c

Compile error "import Operation.* cannot be resolved as static resource"

14. What will happen when you attempt to compile and run the following code?

// given enum 
1	package nl.binit.java5.exambase;
2	
3	public enum Color {
4		RED, YELLOW, GREEN
5	}
6	
7	// and a Test class
8	package nl.binit.java5.exam;
9	import static nl.binit.java5.exambase.Color.*;
10	
11	public class Temp {
12	
13		public static final int RED = 13;
14		
15		public static void main(String[] args) {
16			System.out.println(RED);
17		}
18	}

a

Compile error on line 9: Color class is an Enumeration which is not static

b

Compile error on line 13: static memeber RED already used in context

c

Compile warrning on line 16: [Can't override value of an Enum] and ouput RED

d

Compile and ouput 13

15. What will happen when you attempt to compile and run the following code?

// given class
package nl.binit.java5.exambase;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Box<T> {
	protected List<T> problems;

	public Box() {	problems = new ArrayList<T>();	}

	public void add(T thing) {	problems.add(thing);	}

	public T grab() {
		if (problems.size() > 0) {	return problems.remove(0);}
		else {	return null;}
	}
}
// and Test code
1	public static void main(String[] args) {
2		
3		Box<Integer> ints = new Box<Integer>();
4		ints.add(6);
5		Box<Long> longs = new Box<Long>();
6		longs.add(6);
7		System.out.println(ints.grab() + longs.grab());
8	}

a

Compile error in test code on line 6: The method add(Long) in the type Box<Long> is not applicable for the arguments (int)

b

Compile error in test code on line 6: Can't cast int to long

c

Compile error in test code on line 9: The operator + is undefined for the argument type(s) Integer,Long

d

Compile and ouput 12

16. What will happen when you attempt to compile and run the following code?

// given class
package nl.binit.java5.exambase;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Box<T> {
	protected List<T> problems;

	public Box() {	problems = new ArrayList<T>();	}

	public void add(T thing) {	problems.add(thing);	}

	public T grab() {
		if (problems.size() > 0) {	return problems.remove(0);}
		else {	return null;}
	}
}
// and Test code
1	public static void main(String[] args) {
2		
3		Box<Integer> ints = new Box<Integer>();
4		ints.add(6);
5		Box<Object> objects = ints;
6		int value = (Integer)objects.grab();
7		System.out.println(value);
8	}

a

Compile and ouput 6

b

Compile error in test code on line 5: Type mismatch: cannot convert from Box<Integer> to Box<Object>

c

Compile error in test code on line 6: Can't cast Object to int primitive

17. Autoboxing. What will happen when you attempt to compile and run the following code?

// given code
1	int i = 2;
2	Integer i_boxed = 3;
3	i += i_boxed;
4	Integer i_boxed2 = null;
5	i += i_boxed2;
6
7	System.out.println(i);

a

Compile and ouput 2

b

Compile error code on line 5: Type mismatch: cannot convert from Integer int

c

Compile and NullPointerException

18. String Constructor. What will happen when you attempt to compile and run the following code?

// given code
	public static void main(String[] args) {
		String one = "ONE";
		String another_one = "ONE";
		System.out.print(one.equals(another_one));
		System.out.print(one == another_one);

		char[] one_chars = { 'O', 'N', 'E' };
		String one_again = new String(one_chars);

		char[] another_chars = { 'O', 'N', 'E' };
		String another_one_again = new String(another_chars);

		System.out.print(one_again.equals(another_one_again));
		System.out.print(one_again == another_one_again);
	}

a

Compile and ouput truefalsetruefalse

b

Compile and ouput truetruetruefalse

c

Compile and ouput truetruetruetrue

d

None of a, b, c options

19. Before first public release of Java in March 1995, this programming language has another name. What was the name of Java programming language before March 1995?

a

Silk - What webs are made of

b

Oak - oak tree

c

C+- - just more/less dan C