Java Questions 22: Constructors and Data Types

1. Why can't a constructor be marked static?
   Answer:
   Constructors cannot be marked static because they are associated with instantiation.
2. Why can't a constructor be marked final?
   Answer:
   Constructors are not inherited so they can't be overridden, so what is the use of having a final constructor.
3. What is the purpose of a reference variable?
   Answer:
   The purpose of a reference variable is to refer to or acces an object.
4. What type can a reference variable refer to?
   Answer:
   A reference variable can be used to refer to any object of the declared type, or of a subtype of the declared type (a compatible type).
5. For integer types, what is the sequence from small to large?
   Answer:
   
   1. byte - 8
   2. short - 16
   3. int -32
   4. long -64
   
   
6. How can you remember that doubles are larger than floats?
   Answer:
   A double is twice the number of bits as a float (32 X 2 = 64) bits.
   [byte - 8, short - 16, int -32, long - 64, float -32, double -64]
7. What does it mean when datatypes are signed?
   Answer:
   Signed means the datatypes are positive or negative.
8. What do the data types long and double have in common?
   Answer:
   Long and double are both 64 bit.
9. What are the characteristics of the char data type?
   Answer:
   The char type contains a single, 16-bit Unicode character.
10. Which two keywords are not allowed to preceed a constructor?
    Answer:
    Constructors cannot be preceeded by the keywords 1) static or 2) final.