What is an abstract data structure?

Answer 1

Abstract Data Type in computing is a set of data along with a set of predefined operations.

The actual data inside the ADT is protected from direct manipulation. The exposed operations is the only way to manipulate the data.

In easier terms, it is very much like (though not limited) to the objects in object oriented programming.

Answer 2

Data Type is a characteristic of a datum in programming languages.

Abstract Data Type in computing is an order of a set of data along with a set of operations also.

Answer 3

An abstract data type is any data type that declares a pure-virtual method, or which inherits a pure-virtual method but does not provide an implementation for it.

For example:

shape s; // a 'shapeless' shape

s.draw(); // implausible

Here, shape is an abstract data type. Just as we wouldn't expect to be able to draw a shapeless shape, we wouldn't expect to create one either. Both should be treated as errors by the compiler. This is achieved by making the draw method a pure-virtual method:

struct shape {

virtual void draw()=0; // pure-virtual

// ...

};

Abstract data types are primarily intended to provide interfaces to derived objects. We can do this simply by declaring those methods virtual in the base class, however if we cannot reasonably provide an implementation for an interface, that interface must be declared pure-virtual, thus rendering the entire base class an abstract data type.

The opposite of an abstract class is a concrete class. Only concrete classes can be instantiated in their own right, abstract classes cannot (we can only derive from them).

Answer 4

ADT is a logical description and data structure is concrete. ADT is the logical picture of the data and the operations to manipulate the component elements of the data. Data structure is the actual representation of the data during the implementation and the algorithms to manipulate the data elements. ADT is in the logical level and data structure is in the implementation level.

Answer 5

Abstract is the data type which can be used at method and class level... The abstract keyword which we used at method level makes that method as abstract means not giving implementation for that method.. the abstract keyword which used at the class level , restrict developers not to create the object of that class.

Answer 6

Abstract is not a datatype but a modifier. Abstract can be used in 2 places:

Methods: If a method is termed abstract it means that the current class does not provide an implementation for this method and the first concrete subclass will do the same.

Classes: Any class that has one or more abstract methods has to be abstract. If a class is abstract it means that the implementing class has to provide an implementation for one or more of the abstract methods of this class.

Answer 7

It is a description of what the data stores and what operations you can do on it, without going into details about the actual implementation (i.e., about the data structures). For more details, the Wikipedia article on "abstract data types" has a good summary.