Oracle 1Z0-803 Online Practice Questions and Exam Preparation

Oracle 1Z0-803 Online Questions & Answers

• Question 191:

  Which statement initializes a stringBuilder to a capacity of 128?

  A. StringBuilder sb = new String ("128");
  B. StringBuilder sb = StringBuilder.setCapacity (128);
  C. StringBuilder sb = StringBuilder.getInstance (128);
  D. StringBuilder sb = new StringBuilder (128);
  D. StringBuilder sb = new StringBuilder (128);

  ---

  (int capacity)

  StringBuilder

  Constructs a string builder with no characters in it and an initial capacity specified by the capacity argument. Note: An instance of a StringBuilder is a mutable sequence of characters. The principal operations on a StringBuilder are the append

  and insert methods, which are overloaded so as to accept data of any type. Each effectively converts a given datum to a string and then appends or inserts the characters of that string to the string builder. The append method always adds

  these characters at the end of the builder; the insert method adds the characters at a specified point.

  Incorrect answers:

  StringBuilder sb = new String("128");

  StringBuilder not String is required.

  setCapacity or getInstance do not work.

• Question 192:

  Given:

  public class Natural {

  private int i;

  void disp() {

  while (i <= 5) {

  for (int i=1; i <=5;) {

  System.out.print(i + " ");

  i++;

  }

  i++;

  }

  }

  public static void main(String[] args) {

  new Natural().disp();

  }

  }

  What is the result?

  A. Prints 1 2 3 4 5 once
  B. Prints 1 3 5 once
  C. Prints 1 2 3 4 5 five times
  D. Prints 1 2 3 4 5 six times
  E. Compilation fails
  D. Prints 1 2 3 4 5 six times

  ---

  1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5

• Question 193:

  Given:

  public class X {

  static int i;

  int j;

  public static void main(String[] args) {

  X x1 = new X();

  X x2 = new X();

  x1.i = 3;

  x1.j = 4;

  x2.i = 5;

  x2.j = 6;

  System.out.println(

  x1.i + " "+

  x1.j + " "+

  x2.i + " "+

  x2.j);

  }

  }

  What is the result?

  A. 3 4 5 6
  B. 3 4 3 6
  C. 5 4 5 6
  D. 3 6 4 6
  C. 5 4 5 6

• Question 194:

  Given:

  

  What is result?

  A. Successful
  B. Unsuccessful
  C. Compilation fails
  D. An exception is thrown at runtime
  C. Compilation fails

• Question 195:

  Given:

  

  A. ns = 50 S = 125 ns = 125 S = 125 ns = 100 S = 125
  B. ns = 50 S = 125 ns = 125 S = 125 ns = 0 S = 125
  C. ns = 50 S = 50 ns = 125 S = 125 ns = 100 S = 100
  D. ns = 50 S = 50 ns = 125 S = 125 ns = 0 S = 125
  B. ns = 50 S = 125 ns = 125 S = 125 ns = 0 S = 125

• Question 196:

  Given the code fragment:

  Int [] [] array = {{0}, {0, 1}, {0, 2, 4}, {0, 3, 6, 9}, {0, 4, 8, 12, 16}}; Systemout.printIn(array [4] [1]); System.out.printIn (array) [1] [4]);

  What is the result?

  A. 4 Null
  B. Null
  C. An IllegalArgumentException is thrown at run time
  D. 4 An ArrayIndexOutOfBoundException is thrown at run time
  D. 4 An ArrayIndexOutOfBoundException is thrown at run time

  ---

  The first println statement, System.out.println(array [4][1]);, works fine. It selects the element/array with index 4, {0, 4, 8, 12, 16}, and from this array it selects the element with index 1, 4. Output: 4

  The second println statement, System.out.println(array) [1][4]);, fails. It selects the array/element with index 1, {0, 1}, and from this array it try to select the element with index 4. This causes an exception.

  Output:

  Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 4

• Question 197:

  Given:

  public class ComputeSum {

  public int x;

  public int y;

  public int sum;

  public ComputeSum (int nx, int ny) {

  x = nx; y =ny;

  updateSum();

  }

  public void setX(int nx) { x = nx; updateSum();}

  public void setY(int ny) { x = ny; updateSum();}

  void updateSum() { sum = x + y;}

  }

  This class needs to protect an invariant on the sum field.

  Which three members must have the private access modifier to ensure that this invariant is maintained?

  A. The x field
  B. The y field
  C. The sum field
  D. The ComputerSum ( ) constructor
  E. The setX ( ) method
  F. The setY ( ) method
  C. The sum field
  E. The setX ( ) method
  F. The setY ( ) method

  ---

  The sum field and the two methods (setX and SetY) that updates the sum field.

• Question 198:

  Given:

  

  What is the result?

  A. null
  B. compilation fails
  C. Java.lang.NullPointerException
  A. null

  ---

  An array variable (here xx) can very well have the null value.

  Note:

  Null is the reserved constant used in Java to represent a void reference i.e a pointer to nothing. Internally it is just a binary 0, but in the high level Java language, it is a magic constant, quite distinct from zero, that internally could have any

  representation.

• Question 199:

  A method is declared to take three arguments. A program calls this method and passes only two arguments. What is the results?

  A. Compilation fails.
  B. The third argument is given the value null.
  C. The third argument is given the value void.
  D. The third argument is given the value zero.
  E. The third argument is given the appropriate falsy value for its declared type. F) An exception occurs when the method attempts to access the third argument.
  A. Compilation fails.

• Question 200:

  Given:

  

  What is the result?

  

  A. Option A
  B. Option B
  C. Option C
  D. Option D
  C. Option C