package com.niuke_1; import java.util.ArrayList;import java.util.List; public class demo_2 { private List<String> notes = new ArrayList<String>(); public void add(String note){ notes.add(note); } public void add(int location,String note){ notes.add(location,note); } public int getSize(){ int size=notes.size(); return size; } public String getNote(int index){ return notes.get(index); } public void removeNote(int index){ notes.remove(index); } public String[] list(){ int size=getSize(); String[] result_set = new String[size]; notes.toArray(result_set); for (int i = 0; i < notes.size(); i++) { result_set[i]=notes.get(i); } return result_set; } public static void main(String[] args) { // String[] a = new String[2];// a[0] = "first";// a[1] = "second"; demo_2 notebook = new demo_2(); notebook.add("好好学习"); notebook.add("天天向上"); notebook.add(2,"走上人生巅峰"); System.out.println(notebook.getSize()); // System.out.println(notebook.getNote(0));// notebook.removeNote(1); String nb[]=notebook.list(); for (String s:nb) { System.out.println(s); }// for (int i=0; i<nb.length; i++){// System.out.println(nb[i]);// } }}