Java ArrayList clone()方法及实例

Java.util.ArrayList .clone()方法是用来创建所述数组列表的浅层拷贝。它只是创建一个列表的副本。

语法

ArrayList.clone()

参数： 此方法不接受任何参数。

返回值： 该函数返回一个关联列表实例的副本。

下面的程序说明了Java.util.ArrayList.clone()方法。

例子 1:

// Java code to illustrate clone() method
  
import java.io.*;
import java.util.ArrayList;
  
public class ArrayListDemo {
  
    public static void main(String args[])
    {
  
        // Creating an empty ArrayList
        ArrayList<String> list
            = new ArrayList<String>();
  
        // Use add() method
        // to add elements in the list
        list.add("Geeks");
        list.add("for");
        list.add("Geeks");
        list.add("10");
        list.add("20");
  
        // Displaying the list
        System.out.println("First ArrayList: "
                           + list);
  
        // Creating another linked list and copying
        ArrayList sec_list = new ArrayList();
        sec_list = (ArrayList)list.clone();
  
        // Displaying the other linked list
        System.out.println("Second ArrayList is: "
                           + sec_list);
    }
}

输出。

First ArrayList: [Geeks, for, Geeks, 10, 20]
Second ArrayList is: [Geeks, for, Geeks, 10, 20]

例2:

// Java code to illustrate clone() method
  
import java.io.*;
import java.util.ArrayList;
  
public class ArrayListDemo {
  
    public static void main(String args[])
    {
  
        // Creating an empty ArrayList
        ArrayList<Integer> list
            = new ArrayList<Integer>();
  
        // Use add() method
        // to add elements in the list
        list.add(10);
        list.add(20);
        list.add(30);
        list.add(40);
        list.add(50);
  
        // Displaying the list
        System.out.println("First ArrayList: "
                           + list);
  
        // Creating another linked list and copying
        ArrayList sec_list = new ArrayList();
        sec_list = (ArrayList)list.clone();
  
        // Displaying the other linked list
        System.out.println("Second ArrayList is: "
                           + sec_list);
    }
}

输出。

First ArrayList: [10, 20, 30, 40, 50]
Second ArrayList is: [10, 20, 30, 40, 50]