Certified Java Programmer Mock Exam

Question 1

class GFC404 {
  private static int x=1;
  static void m1(int x, int y) {x++; y++;}
  public static void main (String[] args) {
    int y=3; m1(x, y);
    System.out.println(x + "," + y);
}}

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

Question 2

class EBH011 {
  public static void main (String[] args) {
    float a = Float.POSITIVE_INFINITY;
    double b = Double.POSITIVE_INFINITY;
    double c = Double.NaN;
    System.out.print((a == b)+","+(c == c)+","+(c != c));
}}

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

Question 3

class A {
  public static void main(String[] args) {
    char a = 'a'; // 'a' = 97
    char b = 'b'; // 'b' = 98
    System.out.print(a + b + "" + a + b);
}}

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

Question 4

class EBH012 {
  public static void main (String[] args) {
    byte x = 3, y = 5;
    System.out.print((-x == ~x + 1)+","+(-y == ~y + 1));
}}

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

Question 5

class EBH007{
  public static void main (String[] s) {
    byte b = 5;
    System.out.println(b<<33);
}}

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

Question 6

class Sienna {
  static double a;
  static float b;
  static int c;
  static char d;
  public static void main(String[] args) {
    a = b = c = d = 'a';
    System.out.println(a+b+c+d == 4 * 'a');
}}

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

Question 7

interface I1 {}
interface I2 {}
class Base implements I1 {}
class Sub extends Base implements I2 {}
class Silver {
  public static void main(String []args) {
    Base[] base = {new Base()};
    Sub sub[] = new Sub[1];    // 1
    Object obj = base;         // 2
    sub = (Sub[])obj;          // 3
    I1 []i1 = (I1[])obj;       // 4
}}

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

Question 8

class White {
  public static void main(String args[]) {
    int[] i = {1,2,3,4,5};     // 1
    long[] l1 = new long[5];   // 2
    long []l2 = l1;            // 3
    long l3[] = (long[])i;     // 4
    long l4[] = new long[5];   // 5
    l4[1] = i[1];              // 6
}}

A compile-time error is generated at which line?

Question 9

class GFC200 {}
class GFC201 {
  static void m(Object x) {System.out.print("Object");}
  static void m(String x) {System.out.print("String");}
  static void m(GFC200 x) {System.out.print("GFC200");}
  public static void main(String[] args) {
    m(null);
}}

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

Question 10

class UltraViolet {
  public static void main (String[] args) {
    char a = '\u002a'; // Asterisk, *
    char b = '\u0024'; // Dollar Sign, $
    System.out.print(a + b);           // 1
    System.out.print(" ABC" + a + b);  // 2
}}

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

Question 11

class GFC202 {}
class GFC203 extends GFC202 {}
class GFC204 {
  static void m(GFC202 x) {System.out.print("GFC202");}
  static void m(GFC203 x) {System.out.print("GFC203");}
  public static void main(String[] args) {
    m(null);
}}

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

Question 12

class GFC305 {
  static void m1(int[] i1, int[] i2) {
    int i = i1[0]; i1[0] = i2[0]; i2[0] = i;
  }
  public static void main (String[] args) {
    int[] i1 = {1}, i2 = {3}; m1(i1, i2);
    System.out.print(i1[0] + "," + i2[0]);
}}

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

Question 13

class EBH105 {
  static int m(int i) {
    System.out.print(i + ",");
    return 0;
  }
  public static void main (String[] args) {
    int i = 0;
    i = i++ + m(i);
    System.out.print(i);
}}

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

Question 14

class GFC306 {
  static int[] i1 = {1}, i2 = {3};
  static void m1(int[] i1) {
    int[] i3 = i1; i1 = i2; i2 = i3;
  }
  public static void main (String[] args) {
    m1(i1);
    System.out.print(i1[0] + "," + i2[0]);
}}

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

Question 15

class EBH106 {
  public static void main(String args[]) {
    int a = 1;
    a += ++a + a++;
    System.out.print(a);
}}

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

Question 16

class Amber {
  public static void main(String[] args) {
    int[][] a = {{1,2},{0,1,2},{-1,0,2}};  // 1
    Object[] obj = (Object[])a.clone();    // 2
    for(int i = 0; i < obj.length; i++) {  // 3
      int[] ia = (int[])obj[i];            // 4
      System.out.print(ia[i]);             // 5
}}}

A compile-time error is generated at which line?

Question 17

class GFC307 {
  static void m1(int[] i1, int[] i2) {
    i1 = i2 = null;
  }
  public static void main (String[] args) {
    int[] i1 = {1}, i2 = {3}; m1(i1, i2);
    System.out.print(i1[0] + "," + i2[0]);
}}

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

Question 18

class EBH107 {
  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?