Certified Java Programmer Mock Exam

Question 1

class Basics {
  static int x=1;
  void m(int i) {x++;i++;}
  public static void main (String[] args) {
    int y=3;
    m(y);
    System.out.println(x + "," + y);
  }
}

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

Question 2

class A {
  static boolean a;
  static boolean b;
  static boolean c;
  public static void main (String[] args) {
    boolean x = (a = true) || (b = true) && (c = true);
    System.out.print(a + "," + b + "," + c);
  }
}

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

Question 3

class X {
  public static void main(String args[]) {
    double a = 1.0f / 3.0f;
    double b = 1.0d / 3.0f;
    double c = 1.0d / 3.0d;
    System.out.print((a==b) + ",");
    System.out.print((a==c) + ",");
    System.out.print(b==c);
  }
}

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

Question 4

class A {
  static boolean a;
  static boolean b;
  static boolean c;
  public static void main (String[] args) {
    boolean x = a || (b = true) && (c = true);
    System.out.print(a + "," + b + "," + c);
  }
}

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

Question 5

class A {
  public static void main (String[] args) {
    int a = 1 || 2 ^ 3 && 5;
    int b = ((1 || 2) ^ 3) && 5;
    int c = 1 || (2 ^ (3 && 5));
    System.out.print(a + "," + b + "," + c);
  }
}

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

Question 6

class L {
  public static void main (String s[]) {
    int i = 1 | 2 ^ 3 * 2 & 13 | 2;
    System.out.println(i%5);
  }
}

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

Question 7

class Basics {
  private static int x=1;
  static void m(int i) {x++;i++;}
  public static void main (String[] args) {
    int y=3;
    m(y);
    System.out.println(x + "," + y);
  }
}

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

Question 8

class UltraViolet {
  public static void main (String[] args) {
    char a = '\u002a'; // Asterisk
    char b = '\u0024'; // Dollar Sign
    System.out.print(a + b);
    System.out.print(" ABC" + a + b);
  }
}

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

Question 9

1.  interface I1 {}
2.  interface I2 {}
3.  class Base implements I1 {}
4.  class Sub extends Base implements I2 {}
5.  class Gray {
6.    public static void main(String []args) {
7.      Base[] base = {new Base()};
8.      Sub sub[] = {new Sub()};
9.      Object obj = sub;
10.     base = obj;
11.   }
12. }

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

Question 10

class Red {
  public static void main (String[] args) {
    byte a = 1, b = 2, c, d, e;
    c = (byte)a++;
    d = (byte)++b;
    e = (byte)a + b;
    System.out.print(c + d + e);
  }
}

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

Question 11

class M {
  static int m(int i) {
    System.out.print(i + ", ");
    return i;
  }

  public static void main(String s[]) {
    int i=0;
    int j = m(++i) + m(++i) * m(++i) % m(++i) + m(++i);
    System.out.print(j%5);
  }
}

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

Question 12

1. class Purple {
2.   public static void main (String []args) {
3.     int[] i = {1,2,3};
4.     Object obj = i;
5.     i = obj;
6.   }
7. }

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

Question 13

class A {}
class B extends A {}
class C extends B {
  static void m(A x, A y) {System.out.print("AA");}
  static void m(A x, B y) {System.out.print("AB");}
  static void m(B x, A y) {System.out.print("BA");}
  static void m(B x, B y) {System.out.print("BB");}
  public static void main(String[] args) {
    A a;
    B b;
    m(null,null);
    m(a=null,b=null);
    m(b, a);
  }
}

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

Question 14

class S {
  public static void main(String args[]) {
    byte b = -1,c,d;      // 1
    c = (byte)(b >>> 1);  // 2
    d = (byte)(b >>> 25); // 3
    System.out.print(c+","+d);
  }
}

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

Question 15

import java.io.Serializable;
1. class Blue {
2.   public static void main (String args[]) {
3.     int[] i = {1,2,3};
4.     Serializable s = i;
5.     i = (int [])s;
6.   }
7. }

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

Question 16

 1. interface I1 {}
 2. interface I2 {}
 3. class Base implements I1 {}
 4. class Sub extends Base implements I2 {}
 5.
 6. class Red {
 7.   public static void main(String args[]) {
 8.     Sub s1 = new Sub();
 9.     I2 i2 = s1;
10.     I1 i1 = s1;
11.     Base base = s1;
12.     Sub s2 = (Sub)base;
13.   }
14. }

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

Question 17

class L {
  static String m(float i) {return "float";}
  static String m(double i) {return "double";}
  public static void main (String[] args) {
    int a = 1;
    long b = 2;
    System.out.print(m(a)+","+ m(b));
  }
}

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

Question 18

class Blue {
  public static void main (String[] args) {
    byte b1 = (byte)(2 * Byte.MAX_VALUE);
    byte b2 = -1;
    byte b3 = -2;
    byte b4 = -3;
    System.out.println((b1==b2)+","+(b1==b3)+","+(b1==b4));
  }
}

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