Object type (object-oriented programming)

In computer science, an object type (a.k.a. wrapping object) is a datatype which is used in object-oriented programming to wrap a non-object type to make it look like a dynamic object.

Some object-oriented programming languages make a distinction between reference and value types, often referred to as objects and non-objects on platforms where complex value types don't exist, for reasons such as runtime efficiency and syntax or semantic issues. For example, Java has primitive wrapper classes corresponding to each primitive type: Integer and int, Character and char, Float and float, etc. Languages like C++ have little or no notion of reference type; thus, the use of object type is of little interest.

Boxing

Boxing, otherwise known as wrapping, is the process of placing a primitive type within an object so that the primitive can be used as a reference object. For example, lists may have certain methods which arrays might not, but the list might also require that all of its members be dynamic objects. In this case, the added functionality of the list might be unavailable to a simple array of numbers. For a more concrete example, in Java, a LinkedList can change its size, but an array must have a fixed size. One might desire to have a LinkedList of ints, but the LinkedList class only lists references to dynamic objects — it cannot list primitive types, which are value types.