Inner classes and implementation of ArrayList - Data Structures and Problem Solving Using Java - page 586

1 package weiss.util;
2
3 public class ArrayList<AnyType> extends AbstractCollection<AnyType>
4 implements List<AnyType>
5 {
6 private static final int DEFAULT_CAPACITY = 10;
7 private static final int NOT_FOUND = -1;
8
9 private AnyType [ ] theItems;
10 private int theSize;
11 private int modCount = 0;
12
13 public ArrayList( )
14 { clear( ); }
15
16 public ArrayList( Collection<? extends AnyType> other )
17 {
18 clear( );
19 for( AnyType obj : other )
20 add( obj );
21 }
22
23 public int size( )
24 { return theSize; }
25
26 public void clear( )
27 {
28 theSize = 0;
29 theItems = (AnyType []) new Object[ DEFAULT_CAPACITY ];
30 modCount++;
31 }
32
33 public AnyType get( int idx )
34 {
35 if( idx < 0 || idx >= size( ) )
36 throw new ArrayIndexOutOfBoundsException( );
37 return theItems[ idx ];
38 }
39
40 public AnyType set( int idx, AnyType newVal )
41 {
42 if( idx < 0 || idx >= size( ) )
43 throw new ArrayIndexOutOfBoundsException( );
44 AnyType old = theItems[ idx ];
45 theItems[ idx ] = newVal;
46
47 return old;
48 }
49
50 public boolean contains( Object x )
51 { return findPos( x ) != NOT_FOUND; }

figure 15.13
ArrayList
implementation
(part 1)