Java Reference
In-Depth Information
6. The index for
add
(that is,
index2
) is allowed to be one larger than the index for
set
(that is,
index1
). The index for
set
must be strictly less than the size of the
ArrayList
. The index for
add
can also be equal to the size of the
ArrayList
.
7. Yes. The
ArrayList
can contain more than 20 elements. The number
20
used as
an argument to the constructor merely gives the initial memory allocation for the
ArrayList
. More memory is automatically allocated when it is needed.
8 .
for
(Double element : numberList)
System.out.println(element);
9 .
import
java.util.ArrayList;
/**
Class for sorting an ArrayList of Strings lexicographically
(approximately alphabetically).
*/
public class
StringSelectionSort
{
/**
Sorts the ArrayList a so that a.get(0), a.get(1),...,
a.get(a.size()
—
1) are in lexicographic order.
*/
public static void
sort(ArrayList<String> a)
{
int
index, indexOfNextSmallest;
for
(index = 0; index < a.size() 1; index++)
{
//Place the correct value in position index:
indexOfNextSmallest =
indexOfSmallest(index, a);
interchange(index,indexOfNextSmallest, a);
//a.get(0), a.get(1),...,a.get(index)
//are sorted. The rest of the
//elements are in the remaining positions.
}
}
/**
Precondition: i and j are legal indices for the ArrayList a.
Postcondition: The values of a.get(i) and
a.get(j) have been interchanged.
*/
private static void
interchange(
int
i,
int
j, ArrayList<String> a)