Certified Java Programmer Mock Exam

Question 1

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

Which variable can not be substituted for ??? without causing a compile-time error?

Question 2

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

Which variable can not be substituted for ??? without causing a compile-time error?

Question 3

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 variable names can be substituted for ??? without causing a compile-time error?

Question 4

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 program?

Question 5

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 program?

Question 6

class F {
  public void m1() {Z.m1();}      // 1
  private static class Y {
    private static void m1() {
      System.out.print("Y.m1 ");
  }}
  private static class Z {
    private static void m1(){
      System.out.print("Z.m1 ");
      Y.m1();                     // 2
  }}
  public static void main(String[] args) {
    new F().m1();
}}

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

Question 7

class G {
  final String s1 = "G.s1";
  class Z {
    String s1;
    void m1() {System.out.println(???);}
  }
  public static void main(String args[]) {
    G g = new G(); g.new Z().m1();
}}

Which name or expression could be used in place of ??? to cause the program to print "G.s1"?

Question 8

class Outer {
  static class StaticNested {
    static final int a = 25; // 1
    static final int b;      // 2
    static int c;            // 3
    int d;                   // 4
    static {b = 42;}         // 5
  }
  class NonStaticInner {
    static final int e = 25; // 6
    static final int f;      // 7
    static int g;            // 8
    int h;                   // 9
    static {f = 42;}         // 10
}}

Compile-time errors are generated at which lines?

Question 9

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

A compile-time error is generated at which line?

Question 10

class Red {
  static class StaticNested {interface ABC {}}  // 1
  class NonStaticInner {interface DEF {}}       // 2
  interface GHI {}                              // 3
}

A compile-time error is generated at which line?

Question 11

class A {
  private static int counter;
  public static int getCounter(){return counter++;}
  private static int innerCounter;
  public static int getInnerCounter(){return innerCounter++;}
  private String name;
  A() {name = "A" + getCounter();}
  class B {
    private String name;
    B() {
      name = "B" + getInnerCounter();
      System.out.print(A.this.name + name); // 1
  }}
  public static void main(String[] args) {
    new A().new B();  // 2
    A a1 = new A();
    a1.new B();       // 3
    a1.new B();       // 4
}}

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

Question 12

class A {
  private static int counter;
  public static int getCounter(){return counter++;}
  private static int innerCounter;
  public static int getInnerCounter(){return innerCounter++;}
  private String name;
  A() {name = "A" + getCounter();}
  class B {
    private String name;
    B() {
      name = "B" + getInnerCounter();
      System.out.print(A.this.name + name); // 1
  }}
  void m1() {new A().new B();}  // 2
  void m2() {this.new B();}     // 3
  void m3() {new B();}          // 4
  public static void main(String[] args) {
    A a1 = new A();
    a1.m1(); a1.m2(); a1.m3();
}}

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

Question 13

class A {
  private static int counter;
  public static int getCounter(){return counter++;}
  private static int innerCounter;
  public static int getInnerCounter(){return innerCounter++;}
  private String name;
  A() {name = "A" + getCounter();}
  class B {
    private String name;
    B() {
      name = "B" + getInnerCounter();
      System.out.print(A.this.name + name);
  }}
  void m1() {new A().new B();}  // 1
  void m2() {new A.B();}        // 2
  void m3() {new B();}          // 3
  public static void main(String[] args) {
    A a1 = new A();
    a1.m1(); a1.m2(); a1.m3();
}}

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

Question 14

class A {
  private static int counter;
  public static int getCounter(){return counter++;}
  private static int innerCounter;
  public static int getInnerCounter(){return innerCounter++;}
  private String name;
  A() {name = "A" + getCounter();}
  class B {
    private String name;
    B() {
      name = "B" + getInnerCounter();
      System.out.print(A.this.name + name); // 1
  }}
  static void m1() {new A().new B();}  // 2
  static void m2() {this.new B();}     // 3
  static void m3() {new B();}          // 4
  public static void main(String[] args) {
    m1(); m2(); m3();
}}

What are the results of attempting to compile and run the program?