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:

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).
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).

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 );`

Versions of substring()