C language sorting (to be updated)

C Language arrangement （ To be updated ）

Note： according to CSDN C Language skill tree Organized topic ; The original intention is because C Language vs Java,Python More concise , There are not so many fancy language features , It's perfect for practicing algorithm problems .

One 、C The development of language

• C Language features
• C Language standards , May refer to C Language standards , ANSI C, ISO C, GNU C
• C Language compilation process ( Preprocessing , compile ( Sink code ), assembly ( Machine code ), link ), May refer to C The compilation process of the language is explained in detail

Two 、 data type

• Variable type , Life cycle and Scope
• Constant 2 Types ( Values and characters ) and Definition (#define and const)
  Note： Constants can also be function expressions , such as #define MAX(a,b) ((a > b) ? a : b), Reference resources Relational operator ( Judge whether the intervals overlap )
• Data type classification ( Native , The derived , User customization )
  Note：
  • C There is no language bool,string type ; Basic types include Character , floating-point , integer and Empty type ; Derived types include Array , Pointers and functions type ; User defined types include enumeration , Structures and consortia type .
  • C++ The basic types of are C Based on the basic types of language , Added bool type .

3、 ... and 、 Operators and expressions

• Assignment operator ( Pay attention to the problem of simultaneous assignment of multiple variables )
• Arithmetic operator (++i < 100 and i++ < 100 The difference between )
• Relational operator
• Logical operators ( Determine if it's a leap year ,|| and && Use )
• The comma operator , Operator priority and evaluation order ( The comma operator ), May refer to C Language comma expression in for Use in loop statements
  Note： The comma operator is often used in for Circulation head Initialize or increment Multiple variables
  • Pay attention to the processing order of variables
  • From left to right
  • The value of the entire comma expression is the value of the last sub expression .
• sizeof Operator ( Output Space occupied by operands Of Byte size ), May refer to c Language data type byte size and precision
  Note：sizeof It looks like a function when used ( Because there is a pair of parentheses after it ), But he is an operator . His usage is as follows 3 Kind of ：
  • a) sizeof( Variable name ).
  • b) sizeof( Data type name ).
  • c) sizeof Variable name .

Four 、 Statement and control flow

• Three numbers are sorted from small to large （swap In situ exchange ）
• Judge the type of triangle （ Pay attention to the order of judging conditions ）
• switch-case Rating scores
• 99 multiplication table printing （9 That's ok 9 Column ）
• greatest common divisor (m) Sum of least common multiple (q)（ab = mq）, May refer to Find the greatest common divisor by division

5、 ... and 、 Function and program structure

• Function declaration and definition （C Language Focus on the position of the definition of the method relative to the calling statement ）
  Note： Actually python Also pay attention to the position of the method definition relative to the calling statement , Just no function declaration , Only function definitions .
• Formal parameter and actual parameter （ Be careful swap Time arguments are reference types , Incoming address , Formal parameters are pointer types ）
• Print function call sequence （C Language （ compile ） Must pass main Function entry can execute program ,python（ explain ） You don't need to ）
• Going up the stairs （C Language modular design ）, May refer to C Language modular programming
• Internal function （static） And external functions （extern）, May refer to C In language static and extern A detailed explanation of the use of ,C Language keywords static And extern Detailed explanation of
  Note：
  • The header file (.h） Need to pass #define and #endif Define variables and functions
  • The source file can be divided into multiple .c file , Every .c Files can correspond to one .h file , The .h File contains .c Variable or function declaration of file .
  • By default, the global variable is with extern , That is, in the whole source program all Source file Can be accessed and modified in
  • static If you modify a global variable , will Hide the global variable from other source files

6、 ... and 、 Array

7、 ... and 、 The pointer

8、 ... and 、 character string

Nine 、 Structure

Ten 、 Union and enumeration type

11、 ... and 、 An operation

Twelve 、 The preprocessor

13、 ... and 、 file

fourteen 、 Storage management

15、 ... and 、 Standard function library