Java EnumMap clone()

clone() 方法用于将一个EnumMap的数据复制到另一个EnumMap。此方法创建EnumMap的浅表副本。

1 语法

public EnumMap<K, V> clone()  

2 参数

无

3 返回值

返回EnumMap的浅表副本。

4 EnumMap clone()示例1

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * Java EnumMap.clone的例子
 */
import java.util.*;

public class Demo {

    // create an enum
    public enum Tutorial {
        Java, Python, PHP, Android,  AngularJS
    };
    public static void main(String[] args) {
        //创建EnumMap
        EnumMap<Tutorial, String>  map1 =
                new EnumMap<Tutorial, String> (Tutorial.class);
        EnumMap<Tutorial, String>  map2 =
                new EnumMap<Tutorial, String> (Tutorial.class);

        map1.put(Tutorial.Java,"1");
        map1.put(Tutorial.Python,"2");
        map1.put(Tutorial.PHP,"3");
        map1.put(Tutorial.Android,"4");
        map1.put(Tutorial.AngularJS,"5");
        // 第一次打印map
        System.out.println("clone前:");
        System.out.println("map1:"+map1);
        System.out.println("map2:"+map2);
        // 调用clone方法
        map2 = map1.clone();
        //再次打印map
        System.out.println("clone后:");
        System.out.println("map1:"+map1);
        System.out.println("map2:"+map2);
    }
}

输出结果为：

clone前:
map1:{Java=1, Python=2, PHP=3, Android=4, AngularJS=5}
map2:{}
clone后:
map1:{Java=1, Python=2, PHP=3, Android=4, AngularJS=5}
map2:{Java=1, Python=2, PHP=3, Android=4, AngularJS=5}

5 EnumMap clone()示例2

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * Java EnumMap.clone的例子
 */
import java.util.*;

public class Demo {

    //创建枚举
    public enum Days {
        Monday, Tuesday, Wednesday, Thursday
    };
    public static void main(String[] args) {
        //创建EnumMap
        EnumMap<Days, String> map1= new EnumMap<Days, String>(Days.class);
        EnumMap<Days, String> map2= new EnumMap<Days, String>(Days.class);

        map1.put(Days.Monday,"1");
        map1.put(Days.Tuesday,"2");
        map1.put(Days.Wednesday,"3");
        map1.put(Days.Thursday,"4");
        // 第一次打印Map
        System.out.println("clone前:");
        System.out.println("map1:"+map1);
        System.out.println("map2:"+map2);
        // 调用clone方法
        map2 = map1.clone();
        // 再次打印Map
        System.out.println("clone后:");
        System.out.println("map1:"+map1);
        System.out.println("map2:"+map2);
    }
}

输出结果为：

clone前:
map1:{Monday=1, Tuesday=2, Wednesday=3, Thursday=4}
map2:{}
clone后:
map1:{Monday=1, Tuesday=2, Wednesday=3, Thursday=4}
map2:{Monday=1, Tuesday=2, Wednesday=3, Thursday=4}