其次,当我们使用 enum 时,我们无法决定编译器底层是如何对待 enum 的(比如:signed 和 unsigned)。 而标准规定,enum class 默认的底层数据类型是 int,也可以自己手动指定数据类型,语法如下, 代码语言:javascript 代码运行次数:0 运行 AI代码解释 enum class color:unsigned char {red,
public enum MyEnum { @IntValue(1) VALUE1, @IntValue(2) VALUE2, @IntValue(3) VALUE3; public static MyEnum fromInt(int value) { for (MyEnum e : MyEnum.values()) { IntValue annotation = e.getClass().getField(e.name()).getAnnotation(IntValue.class); if (annotation != null && ...
默认的底层数据类型是int,用户可以通过:type(冒号+类型)来指定任何整形(除了wchar_t)作为底层数据类型。 enum class color:unsigned char{red,blue}; enum calss colorb:long long{yellow,black}; 2.5 域 引入了域,要通过域运算符访问,不可以直接通过枚举体成员名来访问(所以我们可以定义相同的枚举体成员而不会...
IConvertible.ToUInt64(IFormatProvider) Converts the current value to a 64-bit unsigned integer based on the underlying type. ISpanFormattable.TryFormat(Span<Char>, Int32, ReadOnlySpan<Char>, IFormatProvider) Tries to format the value of the enum into the provided span of characters.Appli...
Enum provides methods to compare instances of this class, convert the value of an instance to its string representation, convert the string representation of a number to an instance of this class, and create an instance of a specified enumeration and value. You can also treat an enumeration as...
枚举类的底层数据必须是有符号或无符号整型,比如char unsigned int unsigned long,默认为int。 3.前置声明应用 enmuclassClolor:char; //前置声明枚举类 void Foo(Color*p);//前置声明的使用//...enumclassColor:char{RED,GREEN,BLACK,WHITE}; //前置声明的定义...
classPlayer{private:staticconstintnumPlayer=5;... 注意,因为此处是类的成员声明范围内,所以上面只是变量的声明和初始化,而并非定义,因此如果想获取变量的地址,需要在别处另加定义。这个定义不能有任何赋值语句,因为在类内已经规定为const: constintPlayer::numPlayer; C++标准对...
int value3 = 2; ArrivalStatus status3 = (ArrivalStatus) value3; int value4 = (int) status3; The Enum class also includes a ToObject method that converts a value of any integral type to an enumeration value. The following example uses the ToObject(Type, Int32) method to convert an ...
ToObject(Type, Byte) Converts the specified 8-bit unsigned integer to an enumeration member. ToObject(Type, Int16) Converts the specified 16-bit signed integer to an enumeration member. ToObject(Type, Int32) Converts the specified 32-bit signed integer to an enumeration member. ToObject...
Converts the specified 8-bit unsigned integer to an enumeration member. ToObject(Type, Int16) Converts the specified 16-bit signed integer to an enumeration member. ToObject(Type, Int32) Converts the specified 32-bit signed integer to an enumeration member. ...