如果此映射将一个或多个键映射到指定值,则 java.util.EnumMap.containsValue() 方法返回 true .
语法
public boolean containsValue(Object value)
参数
value | 指定其值待测试此映射中是否存在 |
返回值
如果此映射将一个或多个键映射到指定值,则返回 true .
异常
无。示例:
在下面的示例中,java.lang. util.EnumMap.containsValue() 方法用于检查 EnumMap 是否包含映射到指定值的键。
import java.util.*;
public class MyClass {
//创建一个枚举
public enum weekday{
SUN, MON, TUE, WED, THU, FRI, SAT
}
public static void main(String[] args) {
//创建一个EnumMap
EnumMap<weekday,Integer> MyMap =
new EnumMap<weekday,Integer>(weekday.class);
//关联map中的值
MyMap.put(weekday.MON, 1);
MyMap.put(weekday.TUE, 2);
MyMap.put(weekday.WED, 3);
MyMap.put(weekday.THU, 4);
MyMap.put(weekday.FRI, 5);
//打印EnumMap
System.out.println("MyMap contains: " + MyMap);
//检查映射到 7 的任意键
System.out.print("Does MyMap contain any key mapped to 7? - ");
System.out.println(MyMap.containsValue(7));
//检查映射的任意键 5
System.out.print("Does MyMap contain any key mapped to 5? - ");
System.out.println(MyMap.containsValue(5));
}
}
上述代码的输出将是:
MyMap contains: {MON=1, TUE=2, WED=3, THU=4, FRI=5}
Does MyMap contain any key mapped to 7? - false
Does MyMap contain any key mapped to 5? - true