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Ebook Computer science (9th edition): Part 2

(BQ) Part 2 book "Computer science" has contents: Programming languages, software engineering, data abstractions, database systems, artificial intelligence, theory of computation. | Q) Q. Programming Languages o .c. U 6. 1 Historical Perspective Early Generations Machine Independence and Beyond Programming Paradigms 6.2 Traditional Programming Concepts Variables and In this chapter we study programming languages. Our purpose is not to learn a particular language. Rather it is to learn about programming languages. We want to appreciate the commonality as well as the diversity among programming languages and their associated methodologies. Data 'TYpes Data Structure Constants and Literals Assignment Statements Control Statements Comments 6.3 Procedural Units Pro cedures Parameters Functions 6.4 Language Implementation The Translation Process Software Development Packages "6.5 Object-Oriented Programming Classes and Objects C o nstructors Additiona1 Features *6.6 Programming Concurrent Activities *6.7 Declarative Programming Logical Deduction Prolog *Asterisks indicate suggestions for optional sections. 268 Programming languages The development of complex software systems such as operating systems, network software, and the vast array of application software available today would likely be impossible if humans were forced to write programs in machine language. Dealing with the intricate detail associated with such languages while trying to organize com­ plex systems would be a taxing experience, to say the least. Consequently, program­ ming languages similar to our pseudocode have been developed that allow algorithms to be expressed in a form that is both palatable to humans and easily convertible into machine language instructions. Our goal in this chapter is to explore the sphere of computer science that deals with the design and implementation of these languages. 6. 1 Historical Perspective We begin our study by tracing the historical development of programming languages. Early Generations As we learned in Chapter 2, programs for modern computers consist of sequences of instructions that are encoded as numeric digits.