Certified Java Programmer Mock Exam

Question 1

class SRC104 {
  public static void main (String[] args) {
    System.out.print(Math.round(Float.NaN));
}}

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

Question 2

class D {
  public static void main (String args[]) {
    Byte a = new Byte("1");
    byte b = a.byteValue();
    short c = a.shortValue();
    char d = a.charValue();
    int e = a.intValue();
    long f = a.longValue();
    float g = a.floatValue();
    double h = a.doubleValue();
    System.out.print(b+c+d+e+f+g+h);
}}

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

Question 3

class A {
  public static void main (String args[]) {
    Integer i1 = new Integer(1);
    Integer i2 = new Integer(i1);
    System.out.print(i1.equals(i2));
}}

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

Question 4

class C {
  public static void main (String args[]) {
    Long a = new Long(1);
    byte b = a.byteValue();
    short s = a.shortValue();
    char c = a.charValue();
    int d = a.intValue();
    long e = a.longValue();
    float f = a.floatValue();
    double g = a.doubleValue();
    System.out.print(b+s+c+d+e+f+g);
}}

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

Question 5

class B {
  public static void main (String args[]) {
    Double a = new Double(0xFFFF);
    byte b = a.byteValue();
    short c = a.shortValue();
    int e = a.intValue();
    long f = a.longValue();
    float g = a.floatValue();
    double h = a.doubleValue();
    System.out.print(b+","+c+","+ (e+f+g+h == 4 * 0xFFFF));
}}

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

Question 6

Which of the instance creation expressions produce a run-time error?

Question 7

class C {
  public static void main(String[] args) {
    Boolean b1 = Boolean.valueOf(true);
    Boolean b2 = Boolean.valueOf(true);
    Boolean b3 = Boolean.valueOf("TrUe");
    Boolean b4 = Boolean.valueOf("tRuE");
    System.out.print((b1==b2) + ",");
    System.out.print((b1.booleanValue()==b2.booleanValue()) + ",");
    System.out.println(b3.equals(b4));
}}

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

Question 8

Which of the following class instance creation expressions would generate a run-time error?

Question 9

Which of the following are not methods of the java.lang.String class?

Question 10

class SRC105 {
  public static void main(String[] args) {
    double d1 = Math.ceil(0.5);
    double d2 = Math.ceil(1.5);
    System.out.print(d1 + "," + d2);
}}

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

Question 11

class E {
  public static void main (String[] args) {
    Byte b1 = new Byte("1"), b2 = new Byte("1");
    System.out.print((b1==b2)+","+(b1.equals(b2)));
}}

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

Question 12

class B {
  public static void main (String args[]) {
    Integer a = new Integer(256);
    byte b = a.byteValue();
    short c = a.shortValue();
    int e = a.intValue();
    long f = a.longValue();
    float g = a.floatValue();
    double h = a.doubleValue();
    System.out.print(b+","+c+","+ (e+f+g+h == 4 * 256));
}}

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

Question 13

class F {
  static String m(long i) {return "long";}
  static String m(Long i) {return "Long";}
  static String m(double i) {return "double";}
  static String m(Double i) {return "Double";}
  static String m(String i) {return "String";}
  public static void main (String[] args) {
    System.out.print(m(Long.parseLong("1")));
}}

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

Question 14

class D {
  static boolean m(double v) {
    return(v != v == Double.isNaN(v));
  }
  public static void main (String args[]) {
    double d1 = Double.NaN;
    double d2 = Double.POSITIVE_INFINITY;
    double d3 = Double.MAX_VALUE;
    System.out.print(m(d1) + "," + m(d2) + "," + m(d3));
}}

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

Question 15

class E {
  public static void main (String args[]) {
    String s1 = Float.toString(1.0);  // 1
    String s2 = Float.toString(1.0f); // 2
    String s3 = Float.toString(0xf);  // 3
    String s4 = Float.toString(010);  // 4
    String s5 = Float.toString('A');  // 5
}}

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

Question 16

class D {
  public static void main (String[] args) {
    Boolean b1 = new Boolean("trUE");          // 1
    Boolean b2 = new Boolean("What's This?");  // 2
    Boolean b3 = new Boolean(null);            // 3
    System.out.print(b1 + "," + b2 + "," + b3);
}}

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

Question 17

class F {
  public static void main (String[] args) {
    Short s1 = new Short("1"), s2 = new Short("1");
    int a1 = s1.hashCode(), b1 = s2.hashCode();
    System.out.print((s1==s2)+","+(s1.equals(s2))+","+(a1==b1));
}}

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

Question 18

class MWC104 {
  public static void main (String[] args) {
    char[] c = {'a','b','c','d'};
    String s1 = new String(c);
    boolean b = true;
    for (int i = 0; i < s1.length; i++) {
      b &= (c[i] == s1.charAt(i));
    }
    System.out.print(b);
}}

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

Question 19

class MWC202 {
  public static void main (String[] args) {
    StringBuffer sb1 = new StringBuffer("ABC");
    StringBuffer sb2 = new StringBuffer("ABC");
    System.out.print((sb1==sb2)+","+sb1.equals(sb2));
}}

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

Question 20

class MWC203 {
  public static void main (String[] args) {
    String s1 = new String("ABC"), s2 = new String("ABC");
    StringBuffer sb1 = new StringBuffer(s1);
    StringBuffer sb2 = new StringBuffer(s2);
    boolean b1 = s1.hashCode() == s2.hashCode();
    boolean b2 = sb1.hashCode() == sb2.hashCode();
    System.out.print(b1 + "," + b2);
}}

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