Many working principles of IT and CS, such as programming languages, computer architectures, operating systems, network communication, database, graphical user interface (GUI), graphics, image processing, parallel processing, multi-threads, real-time systems, device drivers, data acquisition, algorithms, numerical analysis, and computer game, are based on or reflected in the functionalities and features of C. The experience in C will help students understand the working principles of these important concepts in IT and CS. Therefore, C is required for the CS major in almost all universities.
Academic institutions have a mission to teach technologies that are widely used in the real world so that students have the skills and knowledge that employers need. More than 90 percent of the programs running on our desktops, from operating systems and e-mail clients to Web browsers and word processors, are written in C or its relative, C++ which has extensions to C. Most games and underlying robot control software are written in C or C++. With the knowledge of C, students will not only be able to play games and robots, but also understand their underlying working principles and potentially develop their own games and robots. The Programming Language Popularity Web site (www.langpop.com) and Programming Community Index ( www.tiobe.com) are two of the best known and most authoritative statistical sources. In the Programming Language Popularity Website (dated in June, 2010), C tops the list, C++ ranks the second, Java is the third as shown in Figure 1.
Figure 1: The popularity of different programming languages.
In the Programming Community Index (dated in June, 2010), C and C++ together are the dominant number one (27.6%, with C for 17.9% and C++ for 9.7%) with a huge distance from the number two among all existing programming languages. Java holds the second spot (18.0%). For comparison, Matlab and Fortran have much lower market shares. Matlab ranks 15 (0.6%) and Fortran ranks 35 (0.4%)
C is the language of choice for harware interface. C allows you to access the memory of a computer or microprocessor to manipulate and play with bits and bytes. Device drivers of new hardware devices are typically written in C. Often, C is the only choice and the other alternative is tedious, low-level programming using an assembly language. Therefore, C is the de facto standard of high-level programming language for hardware interface. As a hardware interface language, C is used commonly for data acquisition and real-time control of embedded and mechatronic systems. C is especially useful for applications such as control of robots. The underlying algorithms for control robots are always written in C. Often times, users will also have to write C code to control a robot. For example, programming robots in the FIRST Robotics Competition is typically accomplished in C. Many hardware and software vendors even provide libraries of C code for hardware interfaces. C is also the most widely used language for programming embedded processors, which control everything from automobiles, industrial machinery, medical equipment, and household appliances to traffic lights, vending machines, cell phones, and toys. Of the 9 billion microprocessors manufactured in 2005, 8.8 billion were embedded into products. Most of them were programmed in C or assembly languages.
Computer programming is an essential skill for advanced studies in Science, Technology, Engineering, and Mathematics (STEM) fields. Like in industry, C is also one of the most commonly used programming languages in colleges and universities for teaching and research. Experience indicates that the gateway courses on C or C++ in colleges are often difficult for freshman college students. C or C++ is required by not only CS major, but also many other majors in colleges and universities. C or C++ is the gatekeeper for the Computer Science major in many universities. With experience in C, students are well prepared for advanced studies in colleges and universities.
Note that many embedded systems do not support C++. Therefore, learning to develop programs using a strict C, without advanced C++ features, is critical for many applications including interface to hardware. C++ is a superset of C to a certain degree. However, C++ is a lot more complicated than C. Unfortunately, without a solid foundation in C, it is impossible to fully master object-oriented and many other advanced features in C++.
C is the language of choice for system programming. Because of the performance and portability of C, almost all popular cross-platform programming languages and scripting languages, such as C++, Java, Python, Objective-C, Perl, Ruby, PHP, Lua, and Bash, are implemented in C and borrowed syntaxes and functions heavily from C. They share the similar operators, expressions, repetition statements, control structures, arrays, input and output, and functions. Furthermore, almost all languages can interface with C and C++ to take advantage of a large volume of existing C/C++ libraries. Many of their toolkits, modules or packages are written using C or C++. For example, a scripting language typically uses wrappers around a C or C++ library to create a toolkit or package. Any emerging popular cross-platform languages will very likely also be written in C and must be designed to be able to interface with existing C/C++ libraries.
C does an excellent job of illustrating the underlying working principles of computers, scientific computing, and disciplined software development. Students gain valuable knowledge of such fundamental programming concepts as data types, internal data representations, operators, expressions, loops for repetitions, control structures, arrays, input and output, functions, debugging, etc. Studying C provides a solid foundation for students who want to learn advanced programming skills such as object-oriented programming, event-driven programming, multi-thread programming, real-time programming, embedded programming, network programming, parallel programming, other programming languages, and new and emerging computing paradigms such as grid-computing and cloud computing.
Certain languages and tools are typically used to solve domain specific problems. Therefore, the ability to understand and learn new languages is important. All other modern languages borrowed heavily from C. Once students learned C, it is easy for them to learn by themselves any other computer languages without much difficulty. On the other hand, even if students have learned other programming languages or visual programming, it is generally still quite difficult for them to learn C by themselves, especially for difficult topics such as pointers and linked lists. Computer programming in C needs a disciplined approach. Many people believe that if students start with computer programming using a typeless scripting language first, then they would have even harder time to learn and master C afterwards.
The standardization encourages diverse implementation by different vendors and organizations. Unlike proprietary languages such as Matlab and Mathematica, a standardized programming language is not controlled by a single vendor. A standardized programming language is stable and its evolution is overseen by a technical standard committee made up of business, academic, and organizational representatives with a stake in the language. The existing code written in a standardized language is less likely to break even if compilers or interpreters from different vendors are updated or developed years later. This means what you learned and wrote 30 years ago won't be obsolete and are still useful today and in the future. The first C standard, C89, was released in 1989 by the ANSI X3J11 and ISO S22/WG14 C Standard Committees. The second (and latest) C standard, C99, was ratified in 1999 and added many new features, such as complex numbers, variable length arrays for numerical computing, and support for 64-bit computing. All existing code conforming to the C89 standard can run in a C compiler or interpreter conforming to the C99 standard. As a contrary example, there is no standard for Python. Python 3.0 breaks the code, packages and modules written for the previous versions of Python.
Writing computer programs is essential to solving complex science and engineering problems. Many principles and concepts in STEM disciplines can be illustrated and reinforced through writing programs. C and C++ are more widely used in STEM fields than any other programming languages such as Java, Fortran, or Matlab.
The notion that only future computer scientists or IT professionals need training in computer programming is no longer true. Outside of the IT industry, knowledge of computer programming is an essential skills for careers not only in STEM fields, but also in marketing, advertising, journalism and the creative arts. For example, market researchers may have to use or write programs to analyze a large set of data.
Developing a program to solve a practical problem involves many creative works, including design, logic reasoning, math, etc. It can help students find practical applications of many math concepts such as variables in Algebra I and trigonometry. Debugging a program can also help student improve their reasoning and logical thinking capabilities. The computer-aided problem solving capabilities can be trained using C.