Certified Java Programmer Mock Exam

Question 1

1.  package com.dan.chisholm;
2.  
3.  public class A {
4.    public void m1() {System.out.print("A.m1, ");}
5.    protected void m2() {System.out.print("A.m2, ");}
6.    private void m3() {System.out.print("A.m3, ");}
7.    void m4() {System.out.print("A.m4, ");}
8.  }
9.  
10. class B {
11.   public static void main(String[] args) {
12.     A a = new A();
13.     a.m1();
14.     a.m2();
15.     a.m3();
16.     a.m4();
17.   }
18. }

Assume that the above code appears in a single file named A.java. What is the result of attempting to compile and run the above program?

Question 2

class Basics {
  int x = 1;
  int y = 2;
  public static void main (String[] args) {
    System.out.println(x+y);
  }
}

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

Question 3

1.  public class Basics {}
2.  public class Basics2 {}
3.  public class Basics3 {}
4.  public class Basics4 {}

Assuming these class definitions are contained in a file named Basics.java, what is the result of attempting to compile the contents of the file?

Question 4

Which of the following modifiers can not be used with the abstract modifier in a method declaration?

Question 5

class A {
  public static void main(String[] args) {
    int[] a1 = {1,2,3};
    int []a2 = {4,5,6};
    int a3[] = {7,8,9};
    System.out.print(a1[1]+","+a2[1]+","+a3[1]);
  }
}

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

Question 6

Class A is declared in a file named A.java.
1.  package com.dan.chisholm;
2.  
3.  public class A {
4.    public void m1() {System.out.print("A.m1, ");}
5.    protected void m2() {System.out.print("A.m2, ");}
6.    private void m3() {System.out.print("A.m3, ");}
7.    void m4() {System.out.print("A.m4, ");}
8.  }

Class C is declared in a file named C.java.
9.  package com.dan.chisholm.other;
10.  
11. import com.dan.chisholm.A;
12.  
13. public class C extends A {
14.   public static void main(String[] args) {
15.     C c = new C();
16.  	c.m1();
17.  	c.m2();
18. 	c.m3();
19. 	c.m4();
20.   }
21. }

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

Question 7

class J {
  public static void main(String[] args) {
    int[] a2 = {1,2}, a3 = {3,4,5}, a4 = {6,7,8,9}; // 1
    int[][] a1 = {a2,a3,a4};                        // 2
    System.out.print(a1[0][1]+","+a1[1][2]+","+a1[2][3]);
  }
}

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

Question 8

Which of the following is used to force each thread to reconcile its working copy of a variable with the master copy in main memory?

Question 9

class A {
  static byte m1() {
    final char c = 'b'-'a';
    return c; // 1
  }
  static byte m2() {
    final short s = 2;
    return s; // 2 
  }
  static byte m3(final char c) {
    return c; // 3
  }
  static byte m4(final short s) {
    return s; // 4
  }
  public static void main(String[] args) {
    char c = 'd'-'a';
    short s = 4;
    System.out.print(""+m1()+m2()+m3(c)+m4(s));
  }
}

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

Question 10

class D {
  static int m1(int i) {;
    return i; // 1
  }
  static void m2(int i) {;
    return i; // 2
  }
  static int m3(int i) {;
    return;   // 3
  }
  public static void main(String[] args) {
    System.out.print(""+m1(1)+m2(2)+m3(3)); // 4
  }
}

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

Question 11

Which of the following statements are true?

Question 12

class A {
  A() throws Exception {}  // 1
}
class B extends A {
  B() throws Exception {}  // 2
}
class C extends A {
  C() {}                   // 3
}

Which of the following statements are true?

Question 13

Which of the following modifiers can be applied to a constructor?

Question 14

class B {
  static int m1(byte b) {;
    return b; // 1
  }
  static int m2(char c) {;
    return c; // 2
  }
  static int m3(short s)  {
    return s; // 3
  }
  static int m4(long l) {
    return l; // 4
  }
  static int m5(float f) {
    return f; // 5
  }
  public static void main(String[] args) {
    byte b = 1;
    char c = 'c'-'a';
    short s = 3;
    long l = 4L;
    float f = 5.0f;
    System.out.print(""+m1(b)+m2(c)+m3(s)+m4(l)+m5(f));
  }

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

Question 15

Which of the following statements are true?

Question 16

class A {
  A(int i) {}         // 1
}
class B extends A {}  // 2

Which of the following statements are true?

Question 17

class A {
  void m1() {
    public int a;      // 1
    protected int b;   // 2
    private int c;     // 3
    static int d;      // 4
    transient int e;   // 5
    volatile int f;    // 6
    final int g = 1;   // 7
  }
}

Compile-time errors are generated at which lines?

Question 18

Which of the following statements are true?

Question 19

class A {
  public static void main(String[] args) {
    int[][] a = {{1,2},{3,4,5},{6,7,8,9},{}};
    for (int i = 0; i < a.length; i++) {
      System.out.print(a[i].length+",");
    }
  }
}

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