Certified Java Programmer Mock Exam

Question 1

abstract class A {             // 1
  abstract static void m1();   // 2
  abstract static class B {}   // 3
  static class C extends B {}  // 4
}

Compiler errors are generated at which of the following lines?

Question 2

abstract class A {
  private int x = 4;
  private int y = 2;
  public int x() {return x;}
  public void x(int x) {this.x = x;}
  public int y() {return y;}
  public void y(int y) {this.y = y;}
  public abstract int math();
}
class B {
  static A a1 = new A() {public int math() {return x()+y();}}
  static A a2 = new A() {public int math() {return x()-y();}}
  static A a3 = new A() {public int math() {return x()*y();}}
  static A a4 = new A() {public int math() {return x()/y();}}
  public static void main(String[] args) {
    System.out.print("" + a1.math() +
                          a2.math() +
                          a3.math() +
                          a4.math());
  }
}

What is the result of attempting to compile and run the program?

Question 3

class Z {
  void m1() {
    abstract class A {}      // 1
    final class B {}         // 2
    private class C {}       // 3
    protected class D {}     // 4
    public class E {}        // 5
    static class F {}        // 6
    synchronized class G {}  // 7
    transient class H {}     // 8
    volatile class I {}      // 9
    strictfp class J {}      // 10
  }
}

Which of the follow class declarations results in a compiler error?

Question 4

abstract class A {
  private int x = 4;
  private int y = 2;
  public A(int i1) {x=i1;}
  public int x() {return x;}
  public void x(int x) {this.x = x;}
  public int y() {return y;}
  public void y(int y) {this.y = y;}
  public void incY() {y++;}
  public abstract int math();
}
class B {
  static A a1 = new A(2) {
    {incY();}
    public int math() {return x()+y();}
  };
  public static void main(String[] args) {
    System.out.print(a1.math());
  }
}

What is the result of attempting to compile and run the program?

Question 5

abstract class A {
  private int x = 4;
  private int y = 2;
  public A(int i1, int i2) {x=i1;y=i2;}
  public int x() {return x;}
  public void x(int x) {this.x = x;}
  public int y() {return y;}
  public void y(int y) {this.y = y;}
  public abstract int math();
}
class B {
  static A a1 = new A(2,1) {public int math() {return x()+y();}};
  static A a2 = new A(2,1) {public int math() {return x()-y();}};
  static A a3 = new A(2,1) {public int math() {return x()*y();}};
  static A a4 = new A(2,1) {public int math() {return x()/y();}};
  public static void main(String[] args) {
    System.out.print("" + a1.math() +
                          a2.math() +
                          a3.math() +
                          a4.math());
  }
}

What is the result of attempting to compile and run the program?

Question 6

abstract class A {                   // 1
  abstract synchronized void m1();   // 2
  abstract synchronized class B {}   // 3
  synchronized class C extends B {}  // 4
}

Compiler errors are generated at which of the following lines?

Question 7

Which of the follow are true statements.

Question 8

class A {
  int B;        // 1
  void B() {}   // 2
  class B {}    // 3
}

Compiler errors are generated at which of the following lines?

Question 9

abstract class A {
  private int x = 4;
  private int y = 2;
  public int x() {return x;}
  public void x(int x) {this.x = x;}
  public int y() {return y;}
  public void y(int y) {this.y = y;}
}
interface B {int math();}
class C {
  static class D extends A implements B {
    public int math() {return x()+y();}
  }
  static A a1 = new A() implements B {
    public int math() {return x()+y();}
  };
  public static void main(String[] args) {
    System.out.print(new C.D().math());
    System.out.print(a1.math());
  }
}

What is the result of attempting to compile and run the program?

Question 10

class A {
  private static int f1 = 1;
  private int f2 = 2;
  void m1(int p1, final int p2) {
    int l1 = 5;
    final int l2 = 6;
    Object x = new Object() {
      int a = f1;  // 1
      int b = f2;  // 2
      int c = p1;  // 3
      int d = p2;  // 4
      int e = l1;  // 5
      int f = l2;  // 6
    };

  }
}

Compiler errors are generated at which of the following lines?

Question 11

Which of the following modifiers can be applied to a local class?

Question 12

class D {
  D() {System.out.print("D");}
  class Z {Z(){System.out.print("Z");}}
  public static void main(String args[]) {
    new D.Z();
  }
}

What is the result of attempting to compile and run the above program?

Question 13

class E {
  E() {System.out.print("E");}
  static class Z {Z(){System.out.print("Z");}}
  public static void main(String args[]) {
   new E.Z();
  }
}

What is the result of attempting to compile and run the above program?

Question 14

Which of the follow are true statements.

Question 15

1.  class F {
2.    public void m1() {Z.m1();}
3.    private static class Y {
4.      private static void m1() {
5.        System.out.print("Y.m1 ");
6.      }
7.    }
8.    private static class Z {
9.      private static void m1(){
10.       System.out.print("Z.m1 ");
11.       Y.m1();
12.     }
13.   }
14.   public static void main(String[] args) {
15.     new F().m1();
16.   }
17. }

What is the result of attempting to compile and run the above program?

Question 16

class C {
  private static String s1 = "s1";
  String s2 = "s2";
  C() {m1("s5","s6");}
  void m1(final String s5, String s6) {
    final String s3 = "s3"; String s4 = "s4";
    class Z {
      Z() {
        System.out.print(???);
      }
    }
    new Z();
  }
  public static void main(String args[]) {new C();}
}

Which variables can be substituted for ??? without causing a compiler error?

Question 17

1.  class Red {
2.    private static final int a = 10;
3.    protected static int b = 20;
4.    int c = 30;
5.    static class StaticNested {
6.      int d = a;
7.      int e = b;
8.      int f = c;
9.    }
10.   class NonStaticInner {
11.     int g = a;
12.     int h = b;
13.     int i = c;
14.   }
15. }

What is the result of attempting to compile the program?