Certified Java Programmer Mock Exam


Question 1

class JSC102 {
  public static void main (String[] args) {
    private int x = 1;
    protected int y = 2;
    public int z = 3;
    System.out.println(x+y+z);
}}

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

a. Prints: 123
b. Prints: 1 2 3
c. Prints: 6
d. Run-time error
e. Compile-time error
f. None of the above

Question 2

class JSC105 {
  private static int x;
  protected static int y;
  public static int z;
  public static void main (String[] args) {
    System.out.println(x+y+z);
}}

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

a. Prints nothing.
b. Prints an undefined value.
c. Prints: null
d. Prints: 0
e. Run-time error
f. Compile-time error
g. None of the above

Question 3

class Red {
  public int a;
  public static int b;
  public static void main (String[] in) {
    Red r1 = new Red(), r2 = new Red();
    r1.a++; r1.b++;
    System.out.print(r1.a+", "+r1.b+", "+r2.a+", "+r2.b);
}}

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

a. Prints: 0, 0, 0, 0
b. Prints: 0, 1, 1, 1
c. Prints: 1, 1, 1, 0
d. Prints: 1, 1, 0, 1
e. Prints: 1, 1, 0, 0
f. Prints: 1, 1, 1, 1
g. Compile-time error
h. Run-time error
i. None of the above

Question 4

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

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

a. Prints: x+y
b. Prints: 12
c. Prints: 3
d. Run-time error
e. Compile-time error
f. None of the above

Question 5

Which of the following statements are true?

a. A final method can not be overridden.
b. All methods declared in a final class are implicitly final.
c. The methods declared in a final class must be explicitly declared final or a compile-time error occurs.
d. It is a compile-time error if a private method is declared final.
e. A machine-code generator can inline the body of a final method.

Question 6

abstract class A {}   // 1
transient class G {}  // 2
private class C {}    // 3
static class E {}     // 4

Suppose these are top-level class declarations and not nested class declarations. Which of these declarations would not produce a compile-time error?

a. 1
b. 2
c. 3
d. 4
e. None of the above

Question 7

class JSC103 {
  transient float e = 1;         // 1
  volatile float f = 1;          // 2
  abstract float j = 1;          // 3
  final float g = 1;             // 4
  private final float k = 1;     // 5
  private transient float l = 1; // 6
  volatile final float m = 1;    // 7
}

Compile-time errors are generated at which lines?

a. 1
b. 2
c. 3
d. 4
e. 5
f. 6
g. 7

Question 8

Which of the following statements are true?

a. If an accessible superclass method is static, then any method with the same signature in a subclass must also be static.
b. If a superclass method is synchronized, then the overriding method must also be synchronized.
c. If a superclass method is public, then the overriding method must also be public.
d. If a superclass method is native, then the overriding method must also be native.
e. If a superclass method is protected, then the overriding method must be protected or public.

Question 9

protected class D {}    // 1
synchronized class F {} // 2
volatile class H {}     // 3
final class B {}        // 4

Suppose these are top-level class declarations and not nested class declarations. Which of these declarations would not produce a compile-time error?

a. 1
b. 2
c. 3
d. 4
e. None of the above

Question 10

class JSC104{
  public float a;        // 1
  protected float b;     // 2
  private float c;       // 3
  static float d;        // 4
  synchronized float i;  // 5
}

A compile-time error is generated at which line?

a. 1
b. 2
c. 3
d. 4
e. 5
f. None of the above.

Question 11

class MWC207 {
  public static void main(String[] args) {
    int[][] a1 = {{1;2};{3;4;5};{6;7;8;9}};
    System.out.print(a1[0][1]+","+a1[1][2]+","+a1[2][3]);
}}

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

a. Prints: 14
b. Prints: 16
c. Prints: 1,5,9
d. Prints: 2,4,8
e. Prints: 2,5,9
f. Compile-time error
g. Run-time error
h. None of the above

Question 12

class MWC208 {
  public static void main(String[] args) {
    int[][] a1 = ((1,2),(3,4,5),(6,7,8,9));
    System.out.print(a1[0][1]+","+a1[1][2]+","+a1[2][3]);
}}

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

a. Prints: 14
b. Prints: 16
c. Prints: 1,5,9
d. Prints: 2,4,8
e. Prints: 2,5,9
f. Compile-time error
g. Run-time error
h. None of the above

Question 13

class MWC209 {
  public static void main(String[] args) {
    int[][] a1 = [[1,2],[3,4,5],[6,7,8,9]];
    int[][] a2 = [[1,2],[3,4,5],[6,7,8,9]];
    int[][] a3 = [[1,2],[3,4,5],[6,7,8,9]];
    System.out.print(a1[0][1]+","+a2[1][2]+","+a3[2][3]);
}}

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

a. Prints: 14
b. Prints: 16
c. Prints: 1,5,9
d. Prints: 2,4,8
e. Prints: 2,5,9
f. Compile-time error
g. Run-time error
h. None of the above

Question 14

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?

a. Prints: 14
b. Prints: 16
c. Prints: 1,5,9
d. Prints: 2,4,8
e. Prints: 2,5,9
f. Compile-time error
g. Run-time error
h. None of the above

Question 15

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?

a. 1
b. 2
c. 3
d. 4
e. None of the above

Question 16

class MWC212 {
  public static void main(String[] args) {
    int[] a1[],a2[];  // 1
    int []a3,[]a4;    // 2
    int []a5,a6[];    // 3
    int[] a7,a8[];    // 4
}}

A compile-time error is generated at which line?

a. 1
b. 2
c. 3
d. 4
e. None of the above

Question 17

class MWC206 {
  public static void main (String[] args) {
    int[][] a1 = {{1,2,3},{4,5,6},{7,8,9}};
    for (int i = 0; i < 3; i++) {
      for (int j = 0; j < 3; j++) {
        System.out.print(a1[j][i]);
}}}}

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

a. Prints: 123456789
b. Prints: 147258369
c. Prints: 321654987
d. Prints: 369258147
e. Run-time error
f. Compile-time error
g. None of the above

Question 18

class A11 {public String toString() {return "A11";}}
class A12 {
  public static void main(String[] arg) {
    A11[]     a1 = new A11[1];         // 1
    A11[][]   a2 = new A11[2][];       // 2
    A11[][][] a3 = new A11[3][][];     // 3
    a1[0] = new A11();                 // 4
    a2[0] = a2[1] = a1;                // 5
    a3[0] = a3[1] = a3[2] = a2;        // 6
    System.out.print(a3[2][1][0]);     // 7
}}

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

a. Prints: null
b. Prints: A11
c. Compile-time error at 1.
d. Compile-time error at 2.
e. Compile-time error at 3.
f. Compile-time error at 4.
g. Compile-time error at 5.
h. Compile-time error at 6.
i. Compile-time error at 7.
j. Run-time error
k. None of the above

Question 19


class A13 {}
class A14 {
  public static void main(String[] arg) {
    A13[]     a1 = new A13[1];         // 1
    A13[][]   a2 = new A13[2][1];      // 2
    A13[][][] a3 = new A13[3][3][3];   // 3
    System.out.print(a3[2][2][2]);     // 4
    a1[0] = new A13();                 // 5
    a2[0] = a2[1] = a1;                // 6
    a3[0] = a3[1] = a3[2] = a2;        // 7
    System.out.print(a3[2][2][2]);     // 8
}}

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

a. Prints: null
b. Prints: nullnull
c. Compile-time error at 1.
d. Compile-time error at 2.
e. Compile-time error at 3.
f. Compile-time error at 4.
g. Compile-time error at 5.
h. Compile-time error at 6.
i. Compile-time error at 7.
j. Compile-time error at 8.
k. Run-time error


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