ArrayList:
1 package com.tn.arraylist; 2 3 public class ArrayList { 4 5 Object[] objects=new Object[10]; 6 int index=0; 7 8 public void add(Object o){ 9 if(index==objects.length){ 10 Object[] newobjects=new Object[objects.length*2]; 11 System.arraycopy(objects, 0, newobjects, 0, index); 12 objects=newobjects; 13 } 14 objects[index++]=o; 15 } 16 17 public int size(){ 18 return index; 19 } 20 21 }
客户端测试类Test:
1 package com.tn.arraylist; 2 3 public class Test { 4 public static void main(String[] args) { 5 ArrayList al=new ArrayList(); 6 for(int i=0;i<34;i++){ 7 al.add(new Object()); 8 } 9 System.out.println(al.size()); 10 } 11 }