5. Versions of substring()



Answer:
The program will throw a NullPointerException (and usually stop running).
Notice that there is no object because the reference variable contains null. Since there is no 
 object, there is no length() to run.






Versions of substring()





    

    

    

        

            

                

            

        

    










There are two versions of substring:
substring( int from ) 
Create a new object that contains the characters of the method's string from index from to the end of the string.
Throws an IndexOutOfBoundsException if from is negative or larger than the length of the string.
substring( int from, int to )
Create a new object that contains the characters of the method's string from index from to index to-1.
Throws an IndexOutOfBoundsException if from is negative or if from is larger than to.

There are some tricky rules about the first version of the method:
  1. If from is exactly equal to the length of the original string, a substring is created, but it contains no characters (it is an empty string).
  2. If from is greater than the length of the original string, or a negative value, a IndexOutOfBoundsException is thrown (and for now, your program crashes).










    

        

    





    















Question 5:
What do the following statements create?
Line of code:
New String
String line = "buttercup" ;
String a = line.substring( 6 );
String b = line.substring( 0 );
String c = line.substring( 9 );
String d = line.substring( line.length() );
String e = line.substring( line.length()+1 );
String f = line.substring( -1 );