Dan Chisholm's
Java Programmer Certification Mock Exam

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Question 1

class EBH019 {
  public static void main (String args[]) {
    int i1 = 0xffffffff, i2 = i1 << 1;
    int i3 = i1 >> 1, i4 = i1 >>> 1;
    System.out.print(Integer.toHexString(i2) + ",");
    System.out.print(Integer.toHexString(i3) + ",");
    System.out.print(Integer.toHexString(i4));
}}

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

Question 2

class MCZ20 {
  public static void main (String[] args) {
    // Insert code here.
}}

Which of the following lines can be inserted at the specified location without generating a compile-time error?

Question 3

class G {
  public static void main (String[] args) {
    Integer i1 = new Integer("1"), i2 = new Integer("1");
    StringBuffer sb1 = new StringBuffer("1");
    StringBuffer sb2 = new StringBuffer("1");
    System.out.print(sb1.equals(sb2)+","+i1.equals(i2));
}}

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

Question 4

Which interface of the java.util package offers the specified behavior?

Question 5

import java.util.*;
class GFC110 {
  public static void main (String[] args) {
    Object m = new LinkedHashMap();
    System.out.print((m instanceof Collection)+",");
    System.out.print((m instanceof Map)+",");
    System.out.print(m instanceof List);
}}

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

Question 6

class MWC210 {
  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 program?

Question 7

abstract class A {               // 1 
  private abstract void m1();    // 2
  private abstract class B {}    // 3
  private class C extends B {}   // 4
}

Which line results in a compile-time error?

Question 8

class Level1Exception extends Exception {}
class Level2Exception extends Level1Exception {}
class Level3Exception extends Level2Exception {}
class Brown {
  public static void main(String args[]) {
    int a, b, c, d, f; a = b = c = d = f = 0;
    int x = 2;
    try {
      switch (x) {
        case 1: throw new Level1Exception();
        case 2: throw new Level2Exception();
        case 3: throw new Level3Exception();
    } a++; }
    catch (Level3Exception e) {b++;}
    catch (Level2Exception e) {c++;}
    catch (Level1Exception e) {d++;}
    finally {f++;}
    System.out.print(a+","+b+","+c+","+d+","+f);
}}

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

Question 9

interface A {  
  protected int e = 5;              // 1
  private int f = 6;                // 2
  volatile int g = 7;               // 3
  transient int h = 8;              // 4
  public static final int d = 9;    // 5
}

Which of the field declarations does not result in a compile-time error?

Question 10

class MCZ19 {
  public static void main (String[] args) {
    String a1 = null;        // 1
    String b1 = 'null';      // 2
    String c1 = "null";      // 3
    String d1 = "'null'";    // 4
}}

A compile-time error is generated at which line?

Question 11

class A {void m1() {System.out.print("A.m1");}}
class B extends A {
  void m1() {System.out.print("B.m1");}
  static void m1(String s) {System.out.print(s+",");}
}
class C {
  public static void main (String[] args) {B.m1("main"); new B().m1();}
}

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

Question 12

class MWC111 {
  static void m1(String s1) {
    s1.replace('A','Y'); System.out.print(s1);
  }
  static void m2(String s1) {
    s1 = s1.replace('A','Z'); System.out.print(s1);
  }
  public static void main(String[] s) {
    String s1 = "A"; m1(s1); m2(s1);
    System.out.print(s1);
}}

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

Question 13

class SRC114 {
  static String m(int i) {return "int";}
  static String m(long i) {return "long";}
  static String m(float i) {return "float";}
  static String m(double i) {return "double";}
  public static void main (String[] args) {
    System.out.print(m(Math.random()));
}}

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

Question 14

class H {
  public static void main (String[] args) {
    int i1, i2; Integer i3, i4;
    i1=new Integer(Integer.parseInt("1")).intValue();     // 1
    i3=new Integer(Integer.parseInt("1")).intValue();     // 2
    i2=Integer.parseInt(Integer.valueOf("1").toString()); // 3
    i4=Integer.parseInt(Integer.valueOf("1").intValue()); // 4
}}

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

Question 15

Which interface of the java.util package offers the specified behavior?

Question 16

import java.util.*;
class GFC111 {
  public static void main (String[] args) {
    Object m = new LinkedHashMap();
    System.out.print((m instanceof Collection)+",");
    System.out.print((m instanceof Map)+",");
    System.out.print(m instanceof HashMap);
}}

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

Question 17

class MWC211 {
  public static void main(String[] args) {
    int a1[3];    // 1
    int []a2[];   // 2
    int[   ]a3;   // 3
    int[] a4[];   // 4
}}

A compile-time error is generated at which line?

Question 18

abstract class A {            // 1
  abstract final void m1();   // 2
  abstract final class B {}   // 3
  class C extends B {}        // 4
}

Which line does not result in a compile-time error?

Question 19

class Level1Exception extends Exception {}
class Level2Exception extends Level1Exception {}
class Level3Exception extends Level2Exception {}
class Brown {
  public static void main(String args[]) {
    int a, b, c, d, f; a = b = c = d = f = 0;
    int x = 4;
    try {
      switch (x) {
        case 1: throw new Level1Exception();
        case 2: throw new Level2Exception();
        case 3: throw new Level3Exception();
    } a++; }
    catch (Level3Exception e) {b++;}
    catch (Level2Exception e) {c++;}
    catch (Level1Exception e) {d++;}
    finally {f++;}
    System.out.print(a+","+b+","+c+","+d+","+f);
}}

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

Question 20

Which of the following are modifiers that can be applied to a method declaration within an interface?

Question 21

class EBH020 {
  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 program?

Question 22

class A {
  private void m1 (int i) {
    assert i < 10 : i; System.out.print(i);
  }
  public void m2 (int i) {
    assert i < 10 : i; System.out.print(i);
  }
  public static void main (String[] args) {
    A a = new A(); a.m1(11); a.m2(12);
}}

Which statements are true?

Question 23

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 24

Which of the following are true statements?

Question 25

class B {
  int a, b, c;
  private void setA(int i) {a = i;}
  private void setB(int i) {b = i;}
  private int m1 (int i) {
    c = a + b + i; assert c < 200 : c; return c;
  }
  public static void main (String[] args) {
    B b = new B(); b.setA(50); b.setB(100); b.m1(50);
}}

Which statements are true?

Question 26

class JMM111 {
  public static void main (String[] args) {
    int j = 0;
    for (int i = 0; i < 2; i++) do
      System.out.print(i);
    while (j++ < 2);
}}

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

Question 27

class JMM112 {
  public static void main (String[] args) {
    int j = 0;
    for (int i = 0; i++ < 2;) do
      System.out.print(i);
    while (j++ < 2);
}}

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

Question 28

class A {String s1="A";}
class B extends A {String s1="B";}
class C extends B {String s1="C";}
class D extends C {
  String s1="D";
  void m1() {
    System.out.print(this.s1  + ",");      // 1
    System.out.print(((C)this).s1  + ","); // 2
    System.out.print(((B)this).s1  + ","); // 3
    System.out.print(((A)this).s1);        // 4
  }
  public static void main (String[] args) {
    new D().m1(); // 5
}}

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