Java
What will be the result of this method, if we pass in a Bird object? public void whatIsThis(Animal a) { if (a instanceof Dog) System.out.println("This is a Dog!"); else System.out.println("I don't know what this is"); }
"I don't know what this is"
What is the value of 'count' at line 4? for (int count = 1; count < 5; count++) { count = count + count; } // Line 4
'count' is out of scope at line 4, and no longer exists
for (byte i = 0; i<5; i++) { system.out.print (i); }
01234
What is the output of the following code? int 1 =0; while(i = 4
01XXX
int i = 0; while(i <5) if(i==0)system.out.print(0); i==; system.out.print((i>2?1:2)); }
022111
What is the output of the following code?
13
Which of these is the symbol for an annotation?
@
You need a collection to represent secret agents. Every agent has a unique codename that identifies them, and an Agent object that represents them. The best collection for this would be?
A HashMap< String, Agent >
Which of these is a valid location for an annotation in Java 8?
Before a class declaration Before the use of a type All of these Before a method declaration
Protected data can...
Can be accessed only by classes in the same package, or subclasses
Which of these is a consequnce of removing a method declaration from an interface after it has been implemented?
Code would break whenever an interface reference is used to polymorphicaly call the method in an instance of an implementing class.
Which of these is a consequence of adding a method declaration to an interface after it has been implemented? (Without declaring the method static or default.)
Every implementing subclass would need to add a definition for the new method.
Interfaces are a form of inheritance
FALSE
Java supports multiple inheritance of classes
FALSE
True or False: A class in Java can extend multiple parent classes
FALSE
True or False: A class without a properly defined main() method may be executed directly.
FALSE
True or False: A final class cannot be instantiated
FALSE
True or False: If the class Car extends class Automobile, then an instance of Automobile can access Car methods
FALSE
True or False: If you write a constructor, the compiler will still give you a default, no-argument constructor.
FALSE
True or False: Interface implementation is a form of inheritance
FALSE
True or False: Strings only hold a single a character.
FALSE
True or False: The subclass of an abstract class cannot be abstract.
FALSE
What is the boolean value of this statement? String string1 = "TEST"; string1.equals(string1.toLowerCase());
FALSE
true or False: An array is a type of Collection in Java
FALSE
What is the use of the '%' operator?
It returns the remainder of a division operation between integers
Which of these is NOT true for Java?
Java allows direct manipulation of memory addresses
Which interface does not extend the Collection interface?
Map
Should you catch all Throwable objects?
No, Errors are Throwable, and should not be caught
The "transient" keyword...
Prevents data from being serialized
IndexOutOfBoundsException is what type of Exception?
RunTimeException
Select the option that is true of Strings in Java.
String is a class.
Because LinkedLists in java implement List, they have an index.
TRUE
The equals() method is equivalent to the == operator, unless overridden
TRUE
True or False: A finally block will execute regardless of whether an exception is caught.
TRUE
True or False: An interface can extend more than one interface
TRUE
True or False: Because sets have no ordering, there is no way to retrieve a specific object from a Set immediately.
TRUE
True or False: Inherited behaviors can be overriden in a subclass
TRUE
True or False: Java can be run on any machine that has a JVM
TRUE
True or False: Mapping with annotations requires you to identify the mapped classes in your configuration document.
TRUE
True or False: Static methods can be called without instantiating the class first.
TRUE
True or False: The Object reference can be used to polymorphically store a reference to an instance of any class in Java
TRUE
True or False: The main() method must be static, in order to be executed by the JVM.
TRUE
True or False: The relationship between a class and its members is a, HAS-A" relationship
TRUE
True or False: You can string multiple if...else statements together
TRUE
True or False: You can use both annotations and mapping files in the same project
TRUE
The @Override annotation...
Tells the compiler that the method is intended to override a superclass method
int count = 0; while (count < 2) { System.out.print("Hi "); }
The loop will run forever
4 Which keyword is used to show inheritance in Java?
extends
What is the output of the following code?
f
The keyword "static" means:
something belongs to the class and is globally available to all instances.
