Arraylist相当于动态数组,可以动态的添加或者删除其中的元素。
参考链接
http://beginnersbook.com/2013/12/java-arraylist/
package com.example.arraylisttest;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ArrayList<String> obj = new ArrayList<String>();
// 添加
obj.add("one");
obj.add("two");
obj.add("three");
obj.add("four");
Log.d("debug", obj + "");
// 往指定索引添加
obj.add(0, "five");
obj.add(1, "six");
Log.d("debug", obj + "");
// 删除指定索引
obj.remove(1);
Log.d("debug", obj + "");
// 删除指定元素
obj.remove("three");
Log.d("debug", obj + "");
// 更改
obj.set(0, "seven");
Log.d("debug", obj + "");
}
}
输出结果
03-20 19:58:36.528 5490-5490/? D/debug: [one, two, three, four]
03-20 19:58:36.528 5490-5490/? D/debug: [five, six, one, two, three, four]
03-20 19:58:36.529 5490-5490/? D/debug: [five, one, two, three, four]
03-20 19:58:36.529 5490-5490/? D/debug: [five, one, two, four]
03-20 19:58:36.529 5490-5490/? D/debug: [seven, one, two, four]
Tony Liu
2017-3-20, Shenzhen