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Interactive System A system that allows direct communication between user and computer. |
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Operating System A set of programs that manages all of the computer's resources. |
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Editor An interactive program used to create and modify source programs or data. |
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In the late 1960s and early 1970s, Dennis Ritchie created the C programming language at AT&T Bell Labs. At the time, a group of people within Bell Labs were designing the UNIX operating system. Initially, UNIX was written in assembly language as was the custom for almost all system software in those days. To escape the difficulties of programming in assembly language, Ritchie invented C as a system programming language. C combines the low-level features of an assembly language with the ease of use and portability of a high-level language. UNIX was reprogrammed so that approximately 90 percent was written in C, and the remainder in assembly language. |
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People often wonder where the cryptic name C came from. In the 1960s a programming language named BCPL (Basic Combined Programming Language) had a small but loyal following, primarily in Europe. From BCPL, another language arose with its name abbreviated to B. For his language, Dennis Ritchie adopted features from the B language and decided that the successor to B naturally should be named C. So the progression was from BCPL to B to C. |
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In 1985 Bjarne Stroustrup, also of Bell Labs, invented the C++ programming language. To the C language he added features for data abstraction and object-oriented programming (topics we discuss much later in this book). Instead of naming the language D, the Bell Labs group named it C++ in a humorous vein. As we see later, ++ signifies the increment operation in the C and C++ languages. Given a variable x, the expression x++ means to increment (add one to) the current value of x. Therefore, the name C++ suggests an enhanced (incremented) version of the C language. |
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Although C originally was intended as a system programming language, both C and C++ are widely used today in business, industry, and personal computing. C++ is powerful and versatile, embodying a wide range of programming concepts. In this book you will learn a substantial portion of the language, but C++ incorporates sophisticated features that go well beyond the scope of an introductory programming course. |
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