Free Java SE 8 Programmer I 1Z0-808 Exam Practice Test

Which three statements are true about the structure of a Java class? (Choose three.)

• A class cannot have the same name as its field.
  
• A public class must have a main method.
  
• A class can have final static methods.
  
• A class can have overloaded private constructors.
  
• Fields need to be initialized before use.
  
• Methods and fields are optional components of a class.
  

Which three statements are true about the structure of a Java class? (Choose three.)

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

Which statement best describes encapsulation?

• Encapsulation ensures that classes can be designed so that only certain fields and methods of an object are accessible from other objects.
  
• Encapsulation ensures that classes can be designed so that their methods are inheritable.
  
• Encapsulation ensures that classes can be designed with some fields and methods declared as abstract.
  
• Encapsulation ensures that classes can be designed so that if a method has an argument MyType x, any subclass of MyType can be passed to that method.
  

Which two are benefits of polymorphism? (Choose two.)

• Faster code at runtime
  
• More efficient code at runtime
  
• More dynamic code at runtime
  
• More flexible and reusable code
  
• Code that is protected from extension by other classes
  

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

• sb. deleteAll ();
  
• sb. delete (0, sb. size () );
  
• sb. delete (0, sb. length () );
  
• sb. removeAll ();
  

What is the name of the Java concept that uses access modifiers to protect variables and hide them within a class?

• Encapsulation
  
• Inheritance
  
• Abstraction
  
• Instantiation
  
• Polymorphism
  

Which three statements are true about exception handling? (Choose three.)

• Only unchecked exceptions can be rethrown.
  
• All subclasses of the RuntimeException class are not recoverable.
  
• The parameter in a catch block is of Throwable type.
  
• All subclasses of the RuntimeException class must be caught or declared to be thrown.
  
• All subclasses of the RuntimeException class are unchecked exceptions.
  
• All subclasses of the Error class are not recoverable.
  

Which statement is true about Java byte code?

• It can run on any platform.
  
• It can run on any platform only if it was compiled for that platform.
  
• It can run on any platform that has the Java Runtime Environment.
  
• It can run on any platform that has a Java compiler.
  
• It can run on any platform only if that platform has both the Java Runtime Environment and a Java compiler.
  

Which two statements are true about Java byte code? (Choose two.)

• It can be serialized across network.
  
• It can run on any platform that has a Java compiler.
  
• It can run on any platform.
  
• It has ''.java'' extension.
  
• It can run on any platform that has the Java Runtime Environment.
  

Which three statements describe the object-oriented features of the Java language? (Choose three.)

• Objects cannot be reused.
  
• A subclass must override the methods from a superclass.
  
• Objects can share behaviors with other objects.
  
• A package must contain a main class.
  
• Object is the root class of all other objects.
  
• A main method must be declared in every class.