Java EnumMap put()用法及代码示例

Java中的Java.util.EnumMap.put(key，value)方法用于关联指定的键-值对。在这种情况下，如果重复这些值，则替换较旧的值。

用法:

Enum_Map.put(key, value)

使用的参数：该方法有两个参数。

key–它是与值关联的指定键。
value–它是与指定键关联的值。

返回值：该函数返回与指定键关联的旧值。

以下程序说明了put(key，value)方法的用法原理：
示例1:

// Java program to demonstrate keySet() 
import java.util.*; 
  
// An enum of geeksforgeeks 
public enum gfg { 
    Global_today, 
    India_today, 
    China 
} 
; 
  
class Enum_demo { 
    public static void main(String[] args) 
    { 
  
        EnumMap<gfg, Integer> mp = new 
                 EnumMap<gfg, Integer>(gfg.class); 
  
        // Values are associated 
        mp.put(gfg.Global_today, 799); 
        mp.put(gfg.India_today, 69); 
  
       // Display the initial map 
       System.out.println("The map is: " + mp); 
  
        // Stores the old value associated with the key 
        int prev_value = mp.put(gfg.India_today, 72); 
  
        // Prints the old value 
        System.out.println("Previous value: " + prev_value); 
  
       // Display the final map 
       System.out.println("The final map is: " + mp); 
    } 
}

输出：

The map is: {Global_today=799, India_today=69}
Previous value: 69
The final map is: {Global_today=799, India_today=72}

示例2:

// Java program to demonstrate the working of keySet() 
import java.util.*; 
  
// an enum of geeksforgeeks 
// ranking globally and in india 
public enum gfg { 
    Global_today, 
    India_today, 
    China_today 
} 
; 
  
class Enum_demo { 
    public static void main(String[] args) 
    { 
  
        EnumMap<gfg, Integer> mp = new EnumMap<gfg, Integer>(gfg.class); 
  
        // Values are associated 
        mp.put(gfg.Global_today, 799); 
        mp.put(gfg.India_today, 69); 
  
       // Display the initial map 
       System.out.println("The map is: " + mp); 
  
        // Stores the old value associated with the key 
        int prev_value = mp.put(gfg.Global_today, 800); 
  
        // Prints the old value 
        System.out.println("Previous value: " + prev_value); 
  
       // Display the final map 
       System.out.println("The final map is: " + mp); 
    } 
}

输出：

The map is: {Global_today=799, India_today=69}
Previous value: 799
The final map is: {Global_today=800, India_today=69}

相关用法

注：本文由纯净天空筛选整理自akash1295大神的英文原创作品 EnumMap put() Method in Java。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。