Inner classes and implementation of ArrayList - Data Structures and Problem Solving Using Java - page 587

52 private int findPos( Object x )
53 {
54 for( int i = 0; i < size( ); i++ )
55 if( x == null )
56 {
57 if( theItems[ i ] == null )
58 return i;
59 }
60 else if( x.equals( theItems[ i ] ) )
61 return i;
62
63 return NOT_FOUND;
64 }
65
66 public boolean add( AnyType x )
67 {
68 if( theItems.length == size( ) )
69 {
70 AnyType [ ] old = theItems;
71 theItems = (AnyType []) new Object[ theItems.length * 2 + 1 ];
72 for( int i = 0; i < size( ); i++ )
73 theItems[ i ] = old[ i ];
74 }
75 theItems[ theSize++ ] = x;
76 modCount++;
77 return true;
78 }
79
80 public boolean remove( Object x )
81 {
82 int pos = findPos( x );
83
84 if( pos == NOT_FOUND )
85 return false;
86 else
87 {
88 remove( pos );
89 return true;
90 }
91 }
92
93 public AnyType remove( int idx )
94 {
95 AnyType removedItem = theItems[ idx ];
96 for( int i = idx; i < size( ) - 1; i++ )
97 theItems[ i ] = theItems[ i + 1 ];
98 theSize--;
99 modCount++;
100 return removedItem;
101 }

figure 15.14
ArrayList
implementation
(part 2)