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Seema Sharma, Lovely Professional University Unit 13: Abstract and Abstracting

Notes

Unit 13: Abstract and Abstracting

CONTENTS
Objectives

Introduction
13.1 Abstract Type

13.2 Use of Abstract Types
13.3 Types of Abstract Types

13.4 Abstract Agencies Service

13.5 Summary
13.6 Keywords

13.7 Review Questions

13.8 Further Readings

Objectives

After studying this unit, you will be able to:
• Define abstract type, budget and schedule
• Describe abstract agencies and service.

Introduction

Abstracts, like all summaries, cover the main points of a piece of writing. Unlike executive summaries
written for non-specialist audiences, abstracts use the same level of technical language and expertise
found in the article itself. And unlike general summaries which can be adapted in many ways to meet
various readers’ and writers’ needs, abstracts are typically 150 to 250 words and follow set patterns.
Because readers use abstracts for set purposes, these purposes further define abstracts.

13.1 Abstract Type

In programming languages, an abstract type is a type in a nominative type system which is declared
by the programmer. It may or may not include abstract methods or properties that contains members
which are also shared members of some declared subtype. In many object oriented programming
languages, abstract types are known as abstract base classes, interfaces, traits, mixins, flavors, or
roles. Note that these names refer to different language constructs which are (or may be) used to
implement abstract types.
Two overriding characteristics of abstract classes is that their use is a design issue in keeping with
the best object oriented programming practices, and by their nature are unfinished.

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