Generally speaking, we think proficiency means that at least when you go to recruit, you say that you are proficient in C language and will not be kicked out by HR, so it will take at least 5- 10 years, plus increasing practice. If you can only write some small software or programs, we generally call it C language introduction, which takes about 1-3 months to get started, depending on the input time. Generally, a set of C language courses on the Internet costs less than 2,000 yuan and lasts for several months, which will fully exercise all the abilities of C language. It is not recommended to attend expensive training courses, and it is best to study by yourself or with video, because computer is a major that attaches great importance to knowledge learning and collection. If even C language is difficult to complete by itself, it will be even more difficult to enter the industry.

As for the software source code, of course, a team of programmers or individual developers knocked it out line by line.