Java EnumMap get()

get() 用于获取指定key的映射值。

1 语法

public V get(Object key)  

2 参数

key：需要查询的键。

3 返回值

返回指定键映射到的值。

4 EnumMap get()示例1

package com.yiidian;

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

public class Demo {

    public enum Tutorial {
        CSS, Python, PHP, Java, Javascript
    };
    public static void main(String[] args) {
        EnumMap<Tutorial, String>  map =
                new EnumMap<Tutorial, String> (Tutorial.class);

        map.put(Tutorial.CSS, "1");
        map.put(Tutorial.Python, "2");
        map.put(Tutorial.PHP, "3");
        map.put(Tutorial.Java, "4");
        // 输出Map
        System.out.println("Map: "+map);
        // 查询Tutorial.CSS
        String value = map.get(Tutorial.CSS);
        System.out.println("Tutorial.CSS value: "+value);
        System.out.println("Tutorial.Javascript value: "+ map.get(Tutorial.Javascript));
    }
}

输出结果为：

Map: {CSS=1, Python=2, PHP=3, Java=4}
Tutorial.CSS value: 1
Tutorial.Javascript value: null

5 EnumMap get()示例2

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * Java EnumMap.get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> map= new EnumMap<Days, String>(Days.class);

        map.put(Days.Monday,"1");
        map.put(Days.Tuesday,"2");
        map.put(Days.Wednesday,"3");
        // 输出Map
        System.out.println("Map: "+map);
        // 查询Days.Monday
        String value = map.get(Days.Monday);
        System.out.println("Days.Monday value: "+value);
        System.out.println("Days.Thursday value: "+map.get(Days.Thursday));
    }
}

输出结果为：

Map: {Monday=1, Tuesday=2, Wednesday=3}
Days.Monday value: 1
Days.Thursday value: null