Compared with assembly language, high-level language basically breaks away from the hardware system of the machine and writes programs in a more understandable 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. It can compile and process low-level memory in a simple way.

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

Extended data:

C language composition

1, data type

The data types of C include integer type, character type, real number type or floating point type (single precision and double precision), enumeration type, array type, structure type, * * * * object type, pointer type and null type.

2. Constant and variable

The value of the (1) constant cannot be changed, and the symbol constant name is usually capitalized.

(2) A variable is an amount whose value can be changed by the name of an identifier. An identifier is a series of letters, numbers or underscores that begin with a letter or underscore. Please note that the first character must be a letter or an underscore, otherwise it is an illegal variable name.

Step 3 arrange

If the variable name is followed by a number bracket, the declaration is an array declaration. Strings are also arrays. They end the array with ASCII NULL. It should be noted that the index values in square brackets are counted from 0.

4. Pointer

If a declared variable is preceded by an *, it indicates that it is a pointer variable. In other words, the variable stores an address, and * (especially monocular operator * here, the same below. There is also a binocular operator *) in C language, which is a content operator, meaning to take the content stored in this memory address. Pointer is one of the main characteristics that distinguish C language from other contemporary high-level languages.

5. Line

The string in C language is actually a char array ending with the character' \0'. You don't need a reference library to use character types, but you need some functions in the C standard library to operate on strings. They are different from character arrays. Using these functions requires a reference to the header file.

6. File input/output

In C language, input and output are realized by a set of functions in the standard library. In ANSI C, these functions are defined in the header file.

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