Data Perspective #11

When an object is passed as an argument to a method, this is actually passed.

a) A copy of the object b) The name of the object c) A reference to the object d) None of these; you cannot pass an object

c

If a method has a parameter that is a reference variable, you should make sure the parameter is not equal to__________ before using it in an operation.

a) false

b) 0

c) null

d) Nan

c

If you write this method for a class, it will automatically be called any time you concatenate an object of the class with a string.

a. ToString

b. PlusString

c. StringConvert

d. ConcatString

a

Making an instance of one class a field in another class is called

a. nesting

b. class fielding

c. aggregation

d. concatenation

c

A class whose internal state cannot be changed is known as a(n) _______ class.

a) Foundational b) Concrete c) Mutable d) Immutable

d

The ________________keyword can be used by an object to refer to itself.

a) callingObject b) this c) me d) instance

b

The .NET runtime system periodically performs this process, which automatically removes unreferenced objects from memory.

a) Memory cleansing b) Memory deallocation c) Garbage collection d) Object expungement

c

1. When an object is passed as an argument to a method, the method can access the argument

t

2. A method cannot return a reference to an object.

f

3. You can write a method that returns null.

t

4. Reference variables can be initialized with null, but you cannot assign null to a reference variable after it has been initialized

f

If you try to check a reference variable to determine whether it is equal to null, an exception will be thrown.

f

6. You can pass null as an argument to a method.

t

7. If an immutable class has a mutable object as a field or property, it is permissible for a method in the immutable class to return a reference to the mutable field or property

f

If an immutable class's constructor accepts a reference to a mutable object, that reference should not be stored in a field.

t

9. If a reference field is declared as readonly, it means the internal state of the object that the variable refers to cannot be changed

f

10. When you declare a reference field as readonly, and then initialize it with a reference to an object, the reference variable cannot refer to any other object

t