Java ArrayList clone()方法

java.util.ArrayList.clone() 返回此ArrayList实例的浅表复制。

1 语法

public Object clone()

2 参数

无

3 返回值

返回此ArrayList实例的副本。

4 示例 

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * java.util.ArrayList.clone()方法的例子
 */
import java.util.ArrayList;

public class Demo {
    public static void main(String args[]) {

        // create an empty array list
        ArrayList<StringBuilder> arrlist1 = new ArrayList<StringBuilder>();

        // use add for new value
        arrlist1.add(new StringBuilder("Learning-"));

        // using clone to affect the objects pointed to by the references.
        ArrayList arrlist2 = (ArrayList) arrlist1.clone();

        // appending the string
        StringBuilder strbuilder = arrlist1.get(0);
        strbuilder.append("list1, list2-both pointing to the same StringBuilder");

        System.out.println("The 1st list prints: ");

        // both lists will print the same value, printing list1
        for (int i = 0; i < arrlist1.size(); i++) {
            System.out.print(arrlist1.get(i) + " ");
        }

        System.out.println("The 2nd list prints the same i.e:");

        // both lists will print the same value, printing list2
        for (int i = 0; i < arrlist2.size(); i++) {
            System.out.print(arrlist2.get(i));
        }
    }
}

输出结果为：

The 1st list prints: 
Learning-list1, list2-both pointing to the same StringBuilder The 2nd list prints the same i.e:
Learning-list1, list2-both pointing to the same StringBuilder