Container

A container is a class, a data structure, or an abstract data type (ADT) whose instances are collections of other objects. In other words, they store objects in an organized way that follows specific access rules. The size of the container depends on the number of objects (elements) it contains. Underlying (inherited) implementations of various container types may vary in size and complexity, and provide flexibility in choosing the right implementation for any given scenario.

In other words, a container is a virtual computing device that is created by a virtual environment to simulate a computer with an installed operating system and one or few user applications. As a rule, containers use a lightweight operating system, tailored exclusively for running installed applications.

Curriculum

Main wikipage: CNM Cloud requirements

Overview

Containers can be characterized by the following three properties:

• access, that is the way of accessing the objects of the container. In the case of arrays, access is done with the array index. In the case of stacks, access is done according to the LIFO (last in, first out) order and in the case of queues it is done according to the FIFO (first in, first out) order;
• storage, that is the way of storing the objects of the container;
• traversal, that is the way of traversing the objects of the container.

Container classes are expected to implement methods to do the following:

• create an empty container (constructor);
• insert objects into the container;
• delete objects from the container;
• delete all the objects in the container (clear);
• access the objects in the container;
• access the number of objects in the container (count).

Containers are sometimes implemented in conjunction with iterators.