Enums in Java are a type of class that have a fixed number of instances. These instances, also known as constants, can be assigned values. This can be done by defining a constructor and a private variable in the
publicstatic<TextendsEnum<T>>TvalueOf(Class<T>enumType,Stringname){returnEnum.valueOf(enumType,name);} 1. 2. 3. 上述代码通过反射的valueOf()方法来获取指定枚举类型的值。其中,enumType参数是枚举类型的Class对象,name参数是要获取的枚举值的名称。该方法会返回一个枚举值,如果找不到对应的值,则会抛...
EnumWithMultipleValues.java importjava.util.Arrays;importjava.util.Optional;publicclassEnumWithMultipleValues{publicstaticvoidmain(String[]args){//Print all enum and valuesfor(AccountStatusas:AccountStatus.values()){System.out.println("Status "+as.getCode()+" is : "+as.getFullName());}//Rever...
每个枚举类型都继承自java.lang.Enum,并自动添加了values和valueOf方法。 而每个枚举常量是一个静态常量字段,使用内部类实现,该内部类继承了枚举类。所有枚举常量都通过静态代码块来进行初始化,即在类加载期间就初始化。 另外通过把clone、readObject、writeObject这三个方法定义为final的,同时实现是抛出相应的异常。这样...
It can only be assigned with 4 values. pizzaSize = Size.SMALL; pizzaSize = Size.MEDIUM; pizzaSize = Size.LARGE; pizzaSize = Size.EXTRALARGE; Example 2: Java Enum with the switch statement enum Size { SMALL, MEDIUM, LARGE, EXTRALARGE } class Test { Size pizzaSize; public Test(Size ...
values() 返回枚举类的所有常量; ordinal() 返回枚举常量的序号 valueOf(String name) 返回名为name的枚举常量,如果存在。 //演示 values(), ordinal() 和 valueOf() 方法enumColor { RED, GREEN, BLUE; }publicclassTest {publicstaticvoidmain(String[] args) ...
T, the implicitly declaredpublic static T valueOf(String)method on that enum may be used instead of this method to map from a name to the corresponding enum constant. All the constants of an enum class can be obtained by calling the implicitpublic static T[] values()method of that class...
同时我们可以在Operator.class的相同路径下看到四个内部类的.class文件com/mikan/Day$1.class、com/mikan/Day$2.class、com/mikan/Day$3.class、com/mikan/Day$4.class,也就是说这四个命名字段分别使用了内部类来实现的;同时添加了两个方法values()和valueOf(String);我们定义的构造方法本来只有一个参数,但却...
Returns the enum constant of the specified enum class with the specified name. C# העתק [Android.Runtime.Register("valueOf", "(Ljava/lang/Class;Ljava/lang/String;)Ljava/lang/Enum;", "")] [Java.Interop.JavaTypeParameters(new System.String[] { "T extends java.lang.Enum<T...
for (ActivityTypeEnum item : ActivityTypeEnum.values()) { if (item.getKey().equals(key)) { return item; } } throw new RuntimeException("通过key获取枚举类异常"); } } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.