The C language can be considered an “ancient” programming language, and it is currently the mainstream programming language in embedded systems. Without C language, there would be no various embedded systems and operating systems today. Although C language is the foundation of programming development, to what extent have you mastered it? Let’s take a look at the different levels of proficiency in C language:Beginner Having studied related books on <C Language Programming> in university, you have a decent grasp and have obtained a computer level two certification, just to pass the final exam and get a diploma. Proficiency level: You understand the basic syntax of C language, can solve the chicken and rabbit problem with 100 legs, and can implement bubble sort, etc.Getting Started You have learned to use C language to write programs and develop some small projects, which means you are starting to apply C language in practical applications. Proficiency level: You understand module encapsulation and invocation, function interface declaration and definition, and multi-file programming in C language. You can do some simple C language projects but often need to refer to examples, and most of the time you need to look up information on how to write the code, lacking mastery of statements and syntax.Intermediate You are proficient in C language programming, mastering various syntax without needing to look up references while writing programs. You are aware of various pitfalls in C language programming: memory leaks, segmentation faults, and you are skilled in using complex syntax such as pointers, arrays, double pointers, pointer arrays, and array pointers. You can basically design some applications based on your own ideas.Some Achievements After years of practical programming, you have a thorough understanding of C language programming, deeply understanding various programming techniques and syntax, and continuously reflecting, summarizing, and refining from past programming experiences, significantly improving your programming skills. You know how to use C language for large project development and management; you learn to view C language from the perspective of user needs, software engineering, and project management, deeply understanding the pros and cons of various programming languages. You master various development environments and debugging skills, can quickly locate issues when encountering engineering problems, and possess the ability to independently analyze and solve problems.Ceiling for Ordinary People After years of honing in the field of C language and embedded development, your perspective on problems is no longer limited to C language itself, but extends to the underlying operating mechanisms and hardware principles behind C language. You are familiar with one or several CPU architectures, master assembly languages for several architectures, and learn to use disassembly to analyze the underlying operation of C language; you are familiar with a full-stack knowledge system including compilation principles, operating systems, algorithms, and CPU architecture. In a company’s project development process, when engineers encounter technical problems that cannot be solved for a long time, it usually requires someone of this level to come to the rescue.Expert Experts are common, but true masters are rare. At this level, in addition to the accumulation of work experience, diligent continuous learning, and self-motivation, one generally also needs interest and talent as a buffer. At this point, learning embedded systems and C language is no longer just to meet work or project needs, but driven by interest. Passion and love drive a person to spend more time and energy on programming, often neglecting other aspects of life. They may not pay much attention to hygiene, and their emotional intelligence may not be high, but given time, they will stand out from the crowd, gradually gaining some fame in the community and becoming objects of admiration for those around them. They do not worry about jobs, as if they carry a halo; wherever they go, there is brightness, and their working aura is powerful, having transcended embedded systems and C language itself, possibly inspiring you and filling you with energy, eager to try. Working with them is a pleasant experience, as if playing a high-level game, executing tasks effectively, cooperating skillfully, and occasionally reaching small climaxes, making it exhilarating. Therefore, cherish such people around you, or those with such potential.