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C and C++ perform such promotion for objects of Boolean, character, wide character, enumeration, and short integer types which are promoted to int, and for objects of type float, which are promoted to double. Unlike some other type conversions, promotions never lose precision or modify the value stored in the object. In Java:
In fact, an enum type in Java is actually a special compiler-generated class rather than an arithmetic type, and enum values behave as global pre-generated instances of that class. Enum types can have instance methods and a constructor (the arguments of which can be specified separately for each enum value). All enum types implicitly extend the ...
The boxed object is always a copy of the value object, and is usually immutable. Unboxing the object also returns a copy of the stored value. Repeated boxing and unboxing of objects can have a severe performance impact, because boxing dynamically allocates new objects and unboxing (if the boxed value is no longer used) then makes them eligible ...
In C#, it is possible to enforce a reference with the ref keyword, similar to C++ and in a sense to C. This feature of C# is particularly useful when one wants to create a method that returns more than one object. In Java trying to return multiple values from a method is unsupported unless a wrapper is used, in this case named "Ref". [65]
The C standard's aliasing rules state that an object shall have its stored value accessed only by an lvalue expression of a compatible type. [4] The types float and int32_t are not compatible, therefore this code's behavior is undefined .
Push the value of field of object (or value type) obj, onto the stack. Object model instruction 0x7C ldflda <field> Push the address of field of object obj on the stack. Object model instruction 0xFE 0x06 ldftn <method> Push a pointer to a method referenced by method, on the stack. Base instruction 0x4D ldind.i
Primitive wrapper classes are not the same thing as primitive types. Whereas variables, for example, can be declared in Java as data types double, short, int, etc., the primitive wrapper classes create instantiated objects and methods that inherit but hide the primitive data types, not like variables that are assigned the data type values.
Also (as with structs), the C++ enum keyword is combined with a typedef, so that instead of naming the type enum name, simply name it name. This can be simulated in C using a typedef: typedef enum {Value1, Value2} name; C++11 also provides a second kind of enumeration, called a scoped enumeration. These are type-safe: the enumerators are not ...