What is C Language: Introduction to C Programming

What is C Language?

C is a high-level, general-purpose programming language. It provides a straightforward, consistent, and powerful interface for programming systems, which is why it is widely used for developing system software, application software, and embedded systems.

The C programming language has been highly influential, and many other languages have been derived from it. For example, C++ and Java are two popular modern dialects of C.

C is an excellent choice for system programming, such as developing operating systems, compilers, and network drivers. Despite its popularity, C is not without its criticisms. Some have argued that its syntax could be more complex and easier to learn, while others have noted its lack of standardization as a significant issue. Nevertheless, C remains a widely used and influential language and will probably continue for many years.

History of C language

The C programming language was created at Bell Laboratories in the early 1970s, mainly by Ken Thompson and Dennis Ritchie. For the UNIX operating system, which at the time required applications to be written in assembly language, programmers needed a more user-friendly set of instructions. Assembly programs, which communicate directly with a computer's hardware, are lengthy and complex to debug, and adding new functionality requires a lot of time and effort.

Thompson's first high-level language was named  B after the BCPL system programming language on which it was built. After Bell Labs purchased a Digital Equipment Corporation (DEC) UNIX system model PDP-11, Thompson rewrote B to better match the demands of modern times and better system hardware. As a result, C, B's successor, was created. By 1973, C had matured to the point that it could be used to rewrite the UNIX operating system.

Other programmers needed documentation that detailed how to use C before it could be utilized effectively outside of Bell Labs. In 1978, Brian Kernighan and Dennis Ritchie's book "The C Programming Language," sometimes known as K&R or the "White Book" by C enthusiasts, became the canonical source for C programming. The second edition of K&R, first published in 1988, is still commonly accessible as of this writing. Based on the book, the first pre-standard version of C is K&R C.

Throughout the 1980s, C developers sought to build standards for the language to prevent others from developing their dialects. The American National Standards Institute (ANSI) standard X3.159-1989 became the official U.S. standard for C 1989. In 1990, the International Organization for Standardization (ISO) issued the ISO/IEC 9899:1990 standard. These standards and their later updates are referenced in C versions after K&R. (C89, C90 and C99).

The 1980s saw a surge in operating system development, with C and its use in UNIX being only such instances. Despite its advancements over its predecessors, C was still difficult to use for creating larger software programs. As computers got more powerful, there was a growing demand for a more user-friendly programming environment. This desire pushed programmers to use C to create their compilers and, as a result, new programming languages. These new languages may make it easier to code complex operations with many moving elements. For example, object-oriented programming, a programming method that maximizes a programmer's ability to reuse code, was eased by languages like C++ and Java derived from C.

Want a Top Software Development Job? Start Here!

Full Stack Developer - MERN StackExplore Program

Benefits of C Language Over Other Programming Languages

C is a powerful programming language that offers several benefits over other languages. 

• C is a universal language that can be used for various applications. 
• C is a very efficient language that can write fast and reliable code. 
• C is a portable language, meaning that code written in C can be easily compiled and run on various platforms. 
• C is a well-established language with a large and active community of developers who constantly work on improving it and creating new tools and libraries.

Key Features of C Programming Language

C is a general-purpose computer programming language for system administration, network programming, and embedded software. 

It has several features that make it desirable for these applications: 

• C program syntax is easy to learn and read; this makes debugging code more accessible and faster.
• C programs are relatively short compared to other languages, which reduces the time needed to complete them.
• C is a powerful programming language that enables developers to create sophisticated software systems. 
• The language is fast, efficient, and easy to learn, making it a popular choice for many applications. 
• C is also portable, meaning programs written in C can be easily ported to other platforms.
• C has been around for many years (it was first released in 1979), so many libraries and tools are available that facilitate its use.

Key Concepts: Variables, Data Types, and Constants

Here is the explanation of frequently used concepts in C:

Variables

As evident by the name, the variables hold changeable values. It involves temporary memory allocation to hold and modify the value per the requirement. The values can be assigned to a variable anytime and are defined using standard variable definition syntax. Variables have multiple storage locations, such as heap, data segment or stack, with choice varying per the declaration environment. The common example of a variable in int var = 50;

Constants

Constant refers to a value that remains unchanged. It is assigned in the program when being defined. They are defined using the const keyword or #define. These values are stored in a text segment and retrieved later. Further, constants are read-only values. The common example of constants is const int minuteperhour = 60; or #define minuteperhour 60;

Data Types

Another necessary part of C language basics is data types. It refers to storing varying types of data in data types. Each type requires a different amount of memory and allows only specific operations. The different data types in C are integer, floating, character, double and others. There are three data types: primitive, derived and user-defined datatypes. 

• Primitive data types are basic and store simple values such as integers, decimals, and alphabets. Examples of these data types are int, float, char, double and void.
• Derive data types are obtained from the primitive ones. Their examples include points, arrays and functions.
• Defined by the user, the user-defined data types include enum, structure and union.

C Basic Commands

Let’s write a simple C program using above operators to print Hello World:-

Explanation of the above code:

As it can be easily seen, the program starts with a #. Any line in the C programming language that begins with a # is handled with by the preprocessor at the first stage of the program's execution, the first thing that happens during compilation of this programme is that the line beginning with # is replaced by whatever is in the stdio.h header file.

The following line is 'int main (void)'. This is the start of a function called main, which returns an integer (int) value and takes no arguments (void). It's important to note that every C program we'll see contains one or more functions. The 'Main' function is where the program's execution begins once it has been run. While all other functions are called from within the main or other functions (allowing us to customize the order in which they are called), the main is called first from within the system.

After that, you'll notice a curly bracket ({). This essentially determines a function's initial scope. Usually, near the end, you'll notice a reverse curly bracket (}), which indicates the function's end of scope. All of the instructions contained within these brackets are handled as a portion of the function's body.

In the body of the main function, there are two lines of code. 'printf("\n Hello World \n");. Printf is a function in the system library that outputs formatted strings to STDOUT. It prints anything anyone type inside double quotes (" ") except escape sequences (such as '\n', which is converted to a newline). 'return 0' is the second line of the body. It essentially signals the end of the main function and returns '0' to the function that was called main.

Ultimately, we may expect this code to produce 'Hello World' as its output.

Want a Top Software Development Job? Start Here!

Full Stack Developer - MERN StackExplore Program

Use of C and Key Applications

C is one of the oldest and most fundamental programming languages, and it is extensively used all over the world. C is a fast, portable language with a large library. It is a middle-level language with the advantages of both low-level and high-level languages. And it's disheartening to learn that C programming is becoming less popular by the day. C has left an indelible mark on practically every field and is widely used for application development and system development.

Some applications of the C programming language include:

Operating System

The C programming language was created with the intention of writing UNIX operating systems. Furthermore, the execution time of programs written in C is comparable to that of assembly language, making C the most important component in the development of multiple operating systems. It was used to write the Unix kernel, Microsoft Windows utilities and operating system apps, and a large portion of the Android operating system.

3D Movies

Applications written in C and C++ are commonly used to make 3D videos, because they handle a large quantity of data and do many computations per second, these apps must be extremely efficient and quick. The less time it takes for designers and animators to create movie shots, the more money the corporation saves.

Intermediate Language

C is occasionally used by implementations of other languages as an intermediate language. This method can be used for portability or convenience, as it eliminates the need for machine-specific code generators by using C as an intermediate language. C includes certain characteristics that aid the compilation of generated code, such as line-number preprocessor directives and optional, unnecessary commas at the end of initializer lists. However, some of C's flaws have encouraged the creation of additional C-based languages, such as those that are expressly designed for usage as intermediate languages.

Play an Important Role in the Development of New Programming Language

The program written in C is easy and quick to execute. As a consequence, the C programming language has resulted in the creation of many other languages. C++ (also known as C with classes), C#, Python, Java, JavaScript, Perl, PHP, Verilog, D, Limbo, and the Unix C shell are examples of these languages. Every language employs the C programming language to varying degrees. Python, for example, uses C to provide standard libraries, whereas C++, PHP, and Perl need C for their syntaxes and control architectures.

Embedded Systems

The C programming language is the recommended language for creating embedded system drivers and applications. The availability of machine-level hardware APIs, as well as the presence of C compilers, dynamic memory allocation, and deterministic resource consumption, make this language the most popular.

Advanced Concepts in C

Heading from the introduction to C programming to some of the advanced concepts in C here:

Debugging with gdb

It is an advanced concept that requires an understanding of the tool and programming details. The gdb tool allows developers to optimize, troubleshoot and improve C programs by offering detailed insights into runtime behavior. It also informs about logical and syntactical errors.

Some of the key commands in gdb include:

• Breakpoints that halt the program execution at a specific time for evaluating variable values and program status. It divides the larger code sections into small chunks.
• The step command enables developers to create a single code at a time.
• The next command executes the next function and not the next line.
• Variable value printing is used after the programs mentioned above to print the variable’s current value.

Dynamic Memory Allocation

This concept involves a change in memory size after allocation, i.e., at runtime. The function is valid for Heap as Stack deals with fixed memory size. However, this flexibility is accompanied by speed limitations. The Heap data has lower efficiency owing to its scattered nature. Dynamic memory allocation also involves memory overhead with the requirement of an additional pointer for each memory allocation. Further, releasing the memory is a manual process that requires free usage ().

Dynamic memory is used when developers are unsure of the required memory size, want to avoid memory wastage and deal with scaled data structures. Linked lists and resizing arrays are common examples of dynamic memory allocation.

Recursion

This concept involves function calling itself to solve a problem rather than relying on loops. Recursion breaks down the problem into small components. The operation continues until it interacts with a base case or stopping condition. In such a case, the function starts to return value. Recursion is used when the process includes multiple calculations and repetitive actions and focuses on the result rather than the steps.

Why Learn C Language?

There are a plethora of programming languages to choose from, ranging from the incredibly high level (such as Visual Basic) to the low-level power of assembly, and a wide range of specialized possibilities in between (Perl, Ruby, and Python are good choices for many tasks). Java has also become a popular programming language for certain tasks, in part due to its extensive API and in part due to the virtual machine's security features.

Nonetheless, there are some compelling reasons to master C programming. First, it's been used by programmers for 30 years, and there is a wealth of source code. This means there's a lot to learn and a lot to put into practice. Furthermore, many of the language's problems have been clarified and it's well-understood among programmers, and there are numerous tutorials accessible.

C has become something of a programming universal language as a result of its antiquity and employment as the language of system programming for Unix. C is a fantastic language for describing common programming concepts in a form that most people can understand. Furthermore, many of the principles used in C, such as argc and argv for command line parameters, loop constructions, and variable types, will appear in many other languages we learn, allowing us to communicate with others even if they don't know C in a way that is understandable to both of us.

To add to that, C is in close proximity to the machine. When you're dealing with pointers, bytes, and individual bits, optimization techniques become a lot more intuitive. Understanding exactly how things work below the hood is also useful; it helps a lot when something you're attempting to perform in a higher-level language seems to take a long time or doesn't function at all. You also have a better understanding of advanced issues, such as how connectivity works. It will be a little bit easier with a higher-level programming language, but it will be more difficult to comprehend what's going on, and when things stop working, it's much preferable to know exactly what's going on so you can repair it.

C has 32 keywords, a variety of data types, and a set of system-utilizing functions that make programming simple.

Another property of 'C' programming is its ability to self-extend. Various functions from a library are included in a 'C' program. We have the option of adding our own features and functions to the library. In our application, we can access and use these functions whenever we want. This capability makes working with sophisticated code much easier.

There are a number of compilers on the market that may be used to run programs written in this language.

How C Programming Language Works?

C is a compiled programming language. This mean that we'll have to convert our source files (human-readable text files) into object files (machine-readable text files for microcontrollers, computers, and laptops).

Editing

Writing/editing source code is the initial stage in constructing an application in C. The source code is a text file that contains all of the instructions that must be executed by the machine (understandable by humans).

We can use either a plain text editor (like Notepad) or the IDE's built-in editor. The source code must follow the syntax of the C programming language. After the source file is complete, save it as a *.c file.

We'll need a compiler to compile our source code. We'll need to install a C compiler on our PC and run it manually from the command prompt if we utilize a simple text editor for our source code. An easier method is to utilize an IDE (which should have a compiler) and simply press a menu button to start it.

A preliminary processing phase of the source file is included in the compilation task. A preprocessor is called by the compiler to perform the preprocessing. The preprocessor searches the source code for lines that begin with the # (hash) character. 

Including functions declared externally from our source code is one of the compiler's directives. The preprocessor removes all compiler directives from the original code, but it keeps track of which extra files are required later in the process. A temporary file will be created at the end of the preprocessing, which will be hidden from the user.

The compiler starts after the preparation is finished. Our source file is converted into an object file by the compiler. The object file, also known as machine code, can be interpreted by the computer's or microcontroller's Central Processing Unit.

The object file is complete, however, some undefined references are missing. These undefined references are code fragments that must be fetched from a separate location. The printf() function is the undefined reference in our scenario. We know where to acquire the code for this function because the compiler directive (#includestdio.h>) mentioned it.

stdio.h is a header file (extension *.h) that contains the declaration of our printf() function, among other things. We describe where to get the definition of the printf() function by including the header file.

Linking

At this point, we must gather all of the files required by our application. For the external functions, we'll need the object files as well as the static library files. The external functions utilized in our source file are defined in the static library files (*.lib). The machine code for the printf() function will be stored in the static library file in our scenario.

A linker is the one who does the linking. It will examine all of the object files for undefined references and replace them with the machine code from the library files. We'll have an executable file (*.exe for Windows applications, *.hex for microcontrollers) at the end of the linking procedure.

Loading

The program file must then be loaded into the computer's memory before it can be executed. A loader is in charge of this. The loader is usually included in the executable file by the linker. When we launch the executable, it activates the loader, which loads the program into memory and starts the operation.

Want a Top Software Development Job? Start Here!

Full Stack Developer - MERN StackExplore Program

Future of C Programming Language

There is no doubt that the C programming language is here to stay. it has been around for decades and is still widely used in various applications. While other languages have come and gone, C has remained a popular choice for many developers.

One reason for C's continued popularity is its versatility, and it can be used for a wide range of tasks, from low-level system programming to high-level application development. C is a relatively easy language to learn, making it a good choice for beginners.

Despite its popularity, there is no guarantee that C will be around forever. Languages come and go, and new technologies always have the potential to replace existing ones. However, C will probably remain a popular language for many years.

Career Path in C Programming

C programming is a versatile language used for various applications. As a result, no specific career path is associated with C programming. 

• However, many C programming careers involve software engineering because C programming is often used for developing system software, applications, and drivers. 
• C programming can also be used for creating embedded systems and firmware. 

Therefore, careers that involve working with C programming can be found in various industries, from software development to hardware engineering. So, with skill and experience in hand, you cannot limit what you can achieve!

How to Learn C Programming?

If you want to learn C programming, there are a few things you should keep in mind. 

• First, finding a good resource to teach you the language basics is essential. Once you have a solid foundation, you can start practicing by writing small programs.
• Taking part in online forums or communities dedicated to C programming is also helpful, as you can learn from others struggling with the language. 
• Finally, don't be afraid to ask for help when you get stuck; many people will help beginners to learn C programming.

Future Prospects for C Developers

Despite the rise of modern programming languages, C developers have strong career prospects due to the language's efficiency, portability, and deep integration into system-level programming. C remains the foundation of operating systems, embedded systems, cybersecurity, and high-performance computing. With industries relying on real-time systems, IoT, and automotive software, skilled C developers are in high demand.

As technology advances, C developers will play a crucial role in low-level programming, kernel development, firmware engineering, and cybersecurity applications. Moreover, expertise in C opens doors to fields like AI, robotics, and blockchain, where performance optimization is critical. Learning complementary languages like C++ and Rust can further expand opportunities in software development, gaming, and financial systems, ensuring long-term career growth.

Choose The Right Software Development Program

This table compares various courses offered by Simplilearn, based on several key features and details. The table provides an overview of the courses' duration, skills you will learn, and additional benefits, among other important factors, to help learners decide which course best suits their needs.

Program Name	Full Stack Java Developer Career Bootcamp	Automation Testing Masters Program
Geo	IN	All
University	Simplilearn	Simplilearn
Course Duration	11 Months	11 Months
Coding Experience Required	Basic Knowledge	Basic Knowledge
Skills You Will Learn	15+ Skills Including Core Java, SQL, AWS, ReactJS, etc.	Java, AWS, API Testing, TDD, etc.
Additional Benefits	Interview Preparation Exclusive Job Portal 200+ Hiring Partners	Structured Guidance Learn From Experts Hands-on Training
Cost	$$	$$
	Explore Program	Explore Program

Conclusion 

C’s proximity to the hardware, portability, and resource utilization predictability make it excellent for low-level development of operating system kernels and embedded applications. Its adaptability, efficiency, and high performance make it a perfect choice for data manipulation tools with significant complexity. Many programming languages today are better than C for their intended purposes, but it does not mean they are superior to C in all areas. When it comes to performance, C is still unrivaled. We hope that this article was able to give you a thorough knowledge of the use of the C language and how we can use it in our software development projects.

To learn the A-Z of programming languages, you can enroll in the Full Stack Developer - MERN Stack offered by Simplilearn in collaboration with Caltech CTME. This course is a comprehensive online bootcamp that includes 25 projects, a capstone project, and interactive online classes. In addition to the  Node Js Sqlite and other related concepts, the course also details everything you need to become a full-stack technologist and accelerate your career as a software developer.

Simplilearn also offers free online skill-up courses in several domains, from data science and business analytics to software development, AI, and machine learning. You can take up any of these free courses to upgrade your skills and advance your career.

FAQs

1. Is the C language still worth learning?

Yes, the high demand for C programmers and the search for relevant skills makes C language worth learning. 

2. What are the career opportunities with C knowledge?

Learning the C language can lead to career opportunities as a software developer, web developer, software engineer, database administrator, data scientist, and more.

3. What are some common challenges in learning C?

The requirement of manual memory management, lack of modern features, writing loops and conditional statements are some challenges beginners face while learning the language.