Oracle 1Z0-803 Online Practice Questions and Exam Preparation

Oracle 1Z0-803 Online Questions & Answers

• Question 181:

  Given the code format:

  

  Which code fragment must be inserted at line 6 to enable the code to compile?

  A. DBConfiguration f; return f;
  B. Return DBConfiguration;
  C. Return new DBConfiguration;
  D. Retutn 0;
  B. Return DBConfiguration;

• Question 182:

  Which two items can legally be contained within a java class declaration?

  A. An import statement
  B. A field declaration
  C. A package declaration
  D. A method declaration
  B. A field declaration
  D. A method declaration

  ---

  Reference: http://docs.oracle.com/javase/tutorial/java/javaOO/methods.html

• Question 183:

  Given the code fragment: Which statement is true?

  

  A. After line 8, three objects are eligible for garbage collection
  B. After line 8, two objects are eligible for garbage collection
  C. After line 8, one object is eligible for garbage collection
  D. After line 8, none of the objects are eligible for garbage collection
  C. After line 8, one object is eligible for garbage collection

• Question 184:

  Given: What is the result?

  

  A. Null
  B. Compilation fails
  C. An exception is thrown at runtime
  A. Null

• Question 185:

  Which three statements are true about the structure of a Java class?

  A. A class can have only one private constructor.
  B. A method can have the same name as a field.
  C. A class can have overloaded static methods.
  D. A public class must have a main method.
  E. The methods are mandatory components of a class.
  F. The fields need not be initialized before use.
  A. A class can have only one private constructor.
  B. A method can have the same name as a field.
  C. A class can have overloaded static methods.

  ---

  A: Private constructors prevent a class from being explicitly instantiated by its callers. If the programmer does not provide a constructor for a class, then the system will always provide a default, public no-argument constructor. To disable this

  default constructor, simply add a private no-argument constructor to the class.

  This private constructor may be empty.

  B: The following works fine:

  int cake() {

  int cake=0;

  return (1);

  }

  C: We can overload static method in Java. In terms of method overloading static method are just like normal methods and in order to overload static method you need to provide another static method with same name but different method

  signature.

  Incorrect:

  Not D: Only a public class in an application need to have a main method.

  Not E:

  Example:

  class A

  {

  public string something;

  public int a;

  }

  Q: What do you call classes without methods? Most of the time: An anti pattern.

  Why? Because it faciliates procedural programming with "Operator" classes and data structures. You separate data and behaviour which isn't exactly good OOP.

  Often times: A DTO (Data Transfer Object)

  Read only datastructures meant to exchange data, derived from a business/domain object.

  Sometimes: Just data structure.

  Well sometimes, you just gotta have those structures to hold data that is just plain and simple and has no operations on it.

  Not F: Fields need to be initialtized. If not the code will not compile.

  Example:

  Uncompilable source code - variable x might not have been initialized

• Question 186:

  Given:

  public class String1 {

  public static void main(String[] args) {

  String s = "123";

  if (s.length() >2)

  concat("456");

  for(int x = 0; x <3; x++)

  s += "x";

  System.out.println(s);

  }

  }

  What is the result?

  A. 123
  B. 123xxx
  C. 123456
  D. 123456xxx
  E. Compilation fails
  B. 123xxx

  ---

  The if clause is not applied.

  Note: Syntax of if-statement:

  if ( Statement ) {

  }

• Question 187:

  Given:

  public class FieldInit {

  char c;

  boolean b;

  float f;

  void printAll() {

  System.out.println("c = " + c);

  System.out.println("c = " + b);

  System.out.println("c = " + f);

  }

  public static void main(String[] args) {

  FieldInit f = new FieldInit();

  A. printAll(); } } What is the result?
  B. c = null b = false f = 0.0F
  C. c = 0 b = false f = 0.0f
  D. c = null b = true f = 0.0
  E. c = b = false f = 0.0
  D. c = null b = true f = 0.0

• Question 188:

  Given:

  

  Which constructor initializes the variable x3?

  A. Only the default constructor of class X
  B. Only the no-argument constructor of class Y
  C. Only the no-argument constructor of class Z
  D. Only the default constructor of object class
  C. Only the no-argument constructor of class Z

• Question 189:

  Given:

  

  Which two are possible outputs?

  

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

  ---

  The first println statement, System.out.println("Before if clause");, will always run. If Math.Random() > 0.5 then there is an exception. The exception message is displayed and the program terminates. If Math.Random() > 0.5 is false, then the second println statement runs as well.

  Incorrect answers:

  B: The second println statement would not run.

  C: The first println statement will always run.

• Question 190:

  Given:

  class MarksOutOfBoundsException extends IndexOutOfBoundsException { } public class GradingProcess {

  void verify(int marks) throws IndexOutOfBoundsException { if (marks > 100) {

  throw new MarksOutOfBoundsException();

  }

  if (marks > 50) {

  System.out.print("Pass");

  } else {

  System.out.print("Fail");

  }

  }

  public static void main(String[] args) {

  int marks = Integer.parseInt(args[2]);

  try {

  new GradingProcess().verify(marks));

  } catch(Exception e) {

  System.out.print(e.getClass());

  }

  }

  }

  And the command line invocation:

  Java grading process 89 50 104

  What is the result?

  A. Pass
  B. Fail
  C. Class MarketOutOfBoundsException
  D. Class IndexOutOfBoundsException
  E. Class Exception
  C. Class MarketOutOfBoundsException

  ---

  The value 104 will cause a MarketOutOfBoundsException