Oracle 1Z0-803 Online Practice Questions and Exam Preparation

Oracle 1Z0-803 Online Questions & Answers

• Question 151:

  Which two are Java Exception classes?

  A. SercurityException
  B. DuplicatePathException
  C. IllegalArgumentException
  D. TooManyArgumentsException
  A. SercurityException
  C. IllegalArgumentException

• Question 152:

  Which two statements correctly describe checked exception?

  A. These are exceptional conditions that a well-written application should anticipate and recover from.
  B. These are exceptional conditions that are external to the application, and that the application usually cannot anticipate or recover from.
  C. These are exceptional conditions that are internal to the application, and that the application usually cannot anticipate or recover from.
  D. Every class that is a subclass of RuntimeException and Error is categorized as checked exception.
  E. Every class that is a subclass of Exception, excluding RuntimeException and its subclasses, is categorized as checked exception.
  B. These are exceptional conditions that are external to the application, and that the application usually cannot anticipate or recover from.
  D. Every class that is a subclass of RuntimeException and Error is categorized as checked exception.

  ---

  Checked exceptions:

  *

  (B) represent invalid conditions in areas outside the immediate control of the program (invalid user input, database problems, network outages, absent files)

  *

  are subclasses of Exception

  It's somewhat confusing, but note as well that RuntimeException (unchecked) is itself a subclass of Exception (checked).

  *

  a method is obliged to establish a policy for all checked exceptions thrown by its implementation (either pass the checked exception further up the stack, or handle it somehow)

  Reference: Checked versus unchecked exceptions

• Question 153:

  Which two are valid array declaration?

  A. Object array[];
  B. Boolean array[3];
  C. int[] array;
  D. Float[2] array;
  A. Object array[];
  C. int[] array;

• Question 154:

  Which statement will empty the contents of a StringBuilder variable named sb?

  A. sb.deleteAll();
  B. sb.delete(0, sb.size());
  C. sb.delete(0, sb.length());
  D. sb.removeAll();
  C. sb.delete(0, sb.length());

• Question 155:

  Given:

  import java.util.*;

  public class Ref {

  public static void main(String[] args) {

  StringBuilder s1 = new StringBuilder("Hello Java!"); String s2 = s1.toString();

  List lst = new ArrayList();

  lst.add(s2);

  System.out.println(s1.getClass());

  System.out.println(s2.getClass());

  System.out.println(lst.getClass());

  }

  }

  What is the result?

  A. class java.lang.String class java.lang.String class java.util.ArrayList
  B. class java.lang.Object class java.lang. Object class java.util.Collection
  C. class java.lang.StringBuilder class java.lang.String class java.util.ArrayList
  D. class java.lang.StringBuilder class java.lang.String class java.util.List
  C. class java.lang.StringBuilder class java.lang.String class java.util.ArrayList

  ---

  class java.lang.StringBuilder class java.lang.String class java.util.ArrayList

• Question 156:

  Given the fragment:

  String[][] arra = new String[3][];

  arra[0] = new String[]{"rose", "lily"};

  arra[1] = new String[]{"apple", "berry","cherry","grapes"}; arra[0] = new String[]{"beans", "carrot","potato"}; // insert code fragment here

  Which code fragment when inserted at line '// insert code fragment here', enables the code to successfully change arra elements to uppercase?

  A. String[][] arra = new String[3][]; arra[0] = new String[]{"rose", "lily"}; arra[1] = new String[]{"apple", "berry","cherry","grapes"}; arra[0] = new String[]{"beans", "carrot","potato"}; for (int i = 0; i < arra.length; i++) { for (int j=0; j < arra[i].length; j++) { arra[i][j] = arra[i][j].toUpperCase(); } }
  B. for (int i = 0; i < 3; i++) { for (int j=0; j < 4; j++) { arra[i][j] = arra[i][j].toUpperCase(); } }
  C. for (String a[]:arra[][]) { for (String x:a[]) {
  D. toUpperCase(); } }
  E. for (int i:arra.length) { for (String x:arra) { arra[i].toUpperCase(); } }
  C. for (String a[]:arra[][]) { for (String x:a[]) {

  ---

  Incorrect:

  not A: arra.length is 3, but the subarrays have 2, 3 and 4 elements. Index will be out of bound. not B: The subarrys are of different lengths. Index will be out of bound.

  not D: Compile error.

• Question 157:

  Given the code fragment:

  

  What is the result?

  A. 2
  B. 1
  C. 3
  D. 3
  A. 2

  ---

  Variable b is set to 4.

  Variable b is decreased to 3.

  Variable b is decreased to 2 and then printed. Output: 2 Variable b is printed. Output: 2

• Question 158:

  Given the code fragment: List colors = new ArrayList(); colors.add("green"); colors.add("red"); colors.add("blue"); colors.add("yellow"); colors.remove(2); colors.add(3,"cyan"); System.out.print(colors);

  What is the result?

  A. [green, red, yellow, cyan]
  B. [green, blue, yellow, cyan]
  C. [green, red, cyan, yellow]
  D. Am IndexOutOfBoundsException is thrown at runtime
  A. [green, red, yellow, cyan]

  ---

  First the list [green, red, blue, yellow] is build.

  The blue element is removed:

  [green, red, yellow]

  Finally the element cyan is added at then end of the list (index 3).

  [green, red, yellow, cyan]

• Question 159:

  View the exhibit:

  

  What is the result when this program is executed?

  A. Bob's Name: Bob
  B. Bob's Name: Jian
  C. Nothing prints
  D. Bob's name
  B. Bob's Name: Jian

  ---

  After the statement jian = bob; the jian will reference the same object as bob.

• Question 160:

  Given:

  public class MyClass {

  public static void main(String[] args) {

  String s = " Java Duke ";

  int len = s.trim().length();

  System.out.print(len);

  }

  }

  What is the result?

  A. 8
  B. 9
  C. 11
  D. 10 E. Compilation fails
  B. 9

  ---

  Java - String trim() Method

  This method returns a copy of the string, with leading and trailing whitespace omitted.