%o: means to output data as an octal integer.

%x: means to output data as a hexadecimal integer.

%u: Indicates that data parameters are output as unsigned integers.

%f: Displays ordinary floating-point numbers represented by decimals.

C language is a general computer programming language, which is widely used in the bottom development. The design goal of C language is to provide a programming language that can compile and process low-level memory in a simple way, generate a small amount of machine code and run without any support of running environment.

Although C language provides many low-level processing functions, it still maintains good cross-platform characteristics. C language programs written in standard specifications can be compiled on many computer platforms, even including some embedded processors (single chip microcomputer or MCU) and supercomputers.

In 1980s, in order to avoid the differences of C language grammar used by different developers, the American National Bureau of Standards formulated a complete set of American national standard grammar of C language, called ANSI C, as the original standard of C language. ? [ 1]? At present, the standard C 1 1 released by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) on February 8, 2000 is the third official standard of C language, and it is also the latest standard of C language, which better supports Chinese character function names and.

References:

C language _ Baidu Encyclopedia