Comparable Interface

Objects that have an ordering are compared using the compareTo() method.

3. This is enough to put a collection in order.



Answer:
"apple", "orange", "plum".
This is the order that compareTo() would place the strings.






Comparable<String> Interface





    

    

    

        

            

                

            

        

    








StringA is regarded as less than StringB if StringA would be proceed StringB in a dictionary. For example,



    
        

            
Expression

            
Evaluates to

        

        

            
"apple".compareTo("orange")

            
Negative Integer

        

        

            
"apple".compareTo("plum")

            
Negative Integer

        

        

            
"apple".compareTo("apple")

            
Zero

        

        

            
"orange".compareTo("orange")

            
Zero

        

        

            
"orange".compareTo("apple")

            
Positive Integer

        

    




Only the sign of the returned integer matters if the return value is not zero. The magnitude of a returned integer does not signify anything.


Memory Aide: think of this as subtraction.



    
apple - orange will be negative.
apple - apple will be zero.
orange - apple will be positive.






Question 3:
Examine the following:
    String myPet = "Fido" ;
String stray = "Rex" ;

if ( myPet.compareTo( stray ) < 0 )
  System.out.println( "Good Dog" );
else
  System.out.println( "Bad Dog" );
What is printed?