C Programming: The Basics You Need to Know

Key takeaways 

Originally designed for use with the UNIX operating system, C quickly became a foundational language in software development.

• The C programming language is the basis of C++, C#, and Java, as well as a popular choice for developing operating systems. 

• C is known for its simplicity, portability, dynamic memory management, recursion abilities, and rich standard library. 

• You can learn C programming to begin developing software like embedded systems, operating systems, web browsers, and databases. 

Explore the basics of C programming, its main features, why it’s used, and how programmers apply it today. If you're ready to start building skills in C programming, try the Introductory C Programming Specialization from Duke University, where you'll have to opporutnity to start building algorithms with C. 

What is C programming?

C programming is a staple for operating systems and embedded systems code. Developed initially as a low-level programming language for UNIX, C remains popular today as a simple, barebones language. Today, it’s the basis of languages like C++, C#, and Java, among others.

C programming offers users more control over various parts of a program. This language balances high-level abstractions and low-level control, giving users more freedom to structure and implement code. It’s a procedural language that organizes programs into sequenced functions or procedures.

Although designed for system programming, you can also use C to write compilers, operating systems, and text editors. Programmers also apply C in database systems, numerical analysis and engineering programs, and text-processing software.

Features of C programming language

C continues to be an essential tool for developers in a wide range of applications. Read on to learn about its features. 

1. Simplicity

The language's relatively small set of keywords and features makes it straightforward to learn and understand. It also allows you to break down programs into separate files, making managing and maintaining code easier. C also allows you to reuse functions across different parts of a program.

2. Portable

Thanks to its standard libraries, C programs run on various platforms with minimal changes. The American National Standards Institute (ANSI) made the language a commercial standard when C was gaining popularity. 

3. Dynamic memory management

C offers low-level features to interact with hardware and memory directly. Pointers in C allow you to work with memory and build more complex functions. These features let you program without knowing how much memory you need.

4. Recursion

C language can loop a function many times until it reaches the given conditions. This supports backtracking and code reusability.

5. Libraries

C has a rich standard library that provides functions for various tasks like:

• Mathematical operations

• Resetting error indicators

• Opening specified files

• Ending the program

Libraries save you the effort of creating these functions from scratch.

C vs. C++ programming

C and C++ are separate languages with the same overall syntax, yet C++ builds upon C. Still, C++ has more keywords and an extended grammar. Both are popular languages to use when speed and efficiency are key considerations. Here are some key differences between C and C++:

• C and C++ have different input and output methods.

• C is a procedural language, while C++ can also do object-oriented programming.

• C++ has a standard template library, but C doesn’t.

• C++ lets you containerize code using namespaces.

• C++ supports exception handling to help prevent errors.

How does C programming work?

At a high level, C programmers write source code to be translated into machine code, which the computer's processor can understand and execute according to what the code tells it to do. Here's an overview of how C works:

Write your code.

You’ll write your human-readable source code following the syntax and rules of C. Typically, you write this using a text editor.

Translation

You’ll then compile your code, translating your high-level source code into low-level machine code. This step involves preprocessing, compilation, and assembly.

C programs consist of multiple source files. In this stage, the linker combines your files and resolves references while linking your code with any necessary libraries that provide additional functionality.

Execution

The compilation and linking stages lead to an executable file containing the machine code instructions that tell the computer processor how to perform the defined tasks.

Run the executable file, which fetches and executes each function in your program sequentially. Your C code programming controls the program runtime.

Pros and cons of C programming 

C programming offers many advantages. However, it’s important to consider the drawbacks as well.

Pros

C provides a simple, no-frills language that runs quickly. Programmers can directly access memory and control low-level computer operations, making it the language of choice for operating system development. Additionally, the C programming community is vast, giving you access to numerous resources, libraries, and code examples for learning and problem-solving.

Cons

The C programming language is criticized for treating programmers as infallible. You define all your variables and can’t change them, which opponents suggest allows questionable programming practices.

Some also view letting programmers directly manage memory as a drawback. It can complicate matters and make programs vulnerable to security concerns (e.g., buffer overflows). 

Additionally, C may prove difficult to learn as its language is bare bones. If you want to use linked lists, stacks, queues, and hashmaps, you’ll need to implement them independently.

Applications of C

You'll find C code in a wide range of devices and systems. This versatile language powers everything from small, smart gadgets to high-performance supercomputers. Here are some examples:

• Embedded systems like GPS trackers, smart watches, traffic light controllers, and robotics

• Operating systems, including Microsoft Windows and the OSX of Mac computers

• Language compilers and interpreters, for example, GCC, Clang, and LLVM

• Browsers like Google Chrome and the Google file system

• Databases such as Oracle and MySQL

Read more: What Does a Hardware Engineer Do? Your Guide

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