Int is the key word of C language, which stands for integer class. Int is an identifier that defines integer data, which means that variables are defined as integer types, which are data types in C language. In a general computer, int occupies 4 bytes and 32 bits. In previous microcomputers, int occupied 2 bytes, 16 bits, and int occupied 4 bytes, which only represented integers. Char accounts for 1 byte and can only represent characters.

C language * * * has three basic data types: integer data "short", "int" and "long"; Floating point data float, double, etc. Character data, that is, "char" data, is usually used to represent various characters. In the C language program, * * * has three program structures: sequence structure, selection structure and loop structure. Sequence structure refers to the execution of sentence after sentence from beginning to end, until the last sentence is executed.

Select structure: after reaching a node, decide the branch direction according to the result of one judgment; Loop structure: The loop structure has a loop body with a piece of code in it. For the loop structure, the key is to determine how many times the loop body is executed according to the judgment result.

Expand knowledge:

C language is a process-oriented abstract general programming language, which is widely used in the underlying development. C language can compile and process low-level memory in a simple way. C language is an efficient programming language, which only produces a small amount of machine language and can run without the support of any running environment.

Although C language provides many low-level processing functions, it still maintains the cross-platform characteristics. C language programs written in standard specifications can be compiled on many computer platforms, including embedded processors and supercomputers.

C language is a process-oriented computer programming language, which is different from object-oriented programming languages such as C++, C# and Java. The design goal of C language is to provide a programming language that can compile and process low-level memory in a simple way, only generate a small amount of machine code, and does not need any running environment support at runtime.

C language is faster than assembly language in describing problems, less workload, good readability, easy debugging, modification and transplantation, and the code quality is equivalent to that of assembly language. Generally speaking, C language is only less efficient than the target program generated by assembly language code 10%-20%. So C language can write system software.