Read the manuscript in pieces

/*
     The last battle 

     Finish this game , basic C A general review 

     keyword （ Also called reserved words , See P It's the parking lot , See keywords , It is a symbol with a mark in ）

     Keywords cannot be created by themselves  C Provided    You can't do variable names     
*/

//auto  Declare automatic variables 
//#include<stdio.h>
//int main()
//{
//    {
//       auto int number = 100;// local variable 
//       //auto  Declare automatic variables ( Every local variable is auto Embellished , Automatic creation and automatic destruction are automatic variables ,auto Omit not to write )
//       int number2 = 120;
//       //auto  Omit 
//    }
//    return 0;
//}

//continue End the current cycle , Start next cycle 
//#include<stdio.h>
//int main()
//{
//    int frequency = 1;
//    for (frequency = 1; frequency <= 50; frequency++) {
//        if (frequency == 25) {
//            continue;// When the conditions are met （25）, End the current cycle , Start next cycle , So I can't print 25
//        }
//        printf(" Number of prints ：%d\n", frequency);
//    }
//    return 0;
//}


//extern	 Declare that variables or functions are defined in other files or other locations in this file 
//#include<stdio.h>
//extern number_one;
//int main()
//{
//    printf("%d\n", number_one);
//    return 0;
//}
//extern（ Declaring external symbols ）  You also understand it as using strlen function , Understand it like calling header file   

//go to sentence   Jump statements without conditions     The example I give is not very good , Code loop , Focus on understanding 
//#include<stdio.h>
//int main()
//{
//    printf("1 Don't go to Myanmar \n");
//    GG:// Transfer location , Be sure to add. ：（ The colon ）
//    printf("2 Don't go to Myanmar \n");
//    printf("3 Don't go to Myanmar \n");
//    goto  GG;//   goto It's the portal    To where ？  Transferred to the GG The place of 
//    printf("1 Don't go to Myanmar \n");// Never execute 
//    return 0;
//}


//register   Declare register variables 
//#include<stdio.h>
//int main()
//{
//    register int number = 100;// It is recommended to put this value in the register （ Whether to put it or not depends on the compiler , Just suggest ）
//    return 0;
//}
/*
    register ？？？

    Let's start with a question , Where can the data be stored ？   Network disk （ Baidu network disk ah what ）       Hard disk （C disc ,D Plate, etc. ）      Memory      Advanced caching     register    Do you find that the faster the speed from left to right , The smaller the space    
    In order to improve the computer speed , The computer will put a lot of frequently used data in registers    When you can't find it in the register   Find advanced cache    Layers down   In this way, the speed increases a lot 

*/

//static  Declare static variables    3 A role ;  1. Modify local variables   2. Modify global variable  3. Modify function 

//#include<stdio.h>
//void Test() {
//    static int number = 0;//static After modification , Local variables do not die , It extends the life cycle     Keep the last number++ The results of the implementation of 
//    number++;
//    printf("%d\n", number);
//
//}
//int main()
//{
//    int frequency = 0;
//    
//    while (frequency < 10) {
//        Test();
//        frequency++;
//    }
//    
//    return 0;
//}
//static Changing the life cycle of local variables , Essentially, it changes the storage type of data 
// The storage types of data are    The stack area （ Store local variables and function parameters , You can understand it as storing temporary ）  Heap area （ Dynamic memory allocation , You can understand that there are always changes ）  Static zone （ Deposit static Decorated things and static variables , You can understand it as stored for a long time ）
//static Modify global variable   And functions , It can only be used in this document static Something to decorate ,extern You can't even come 

//define  Used to alias data types 
//#include<stdio.h>
//#define MAX 10000 // Definition MAX The value is 1000( Defining symbols )
//#define ADD(X, Y) X+Y//define Defining macro 
//int main()
//{
//    printf("%d\n", ADD(5, 6));// The result is 11
//    printf("%d\n", 5 * ADD(5, 6)); // amount to    5*5+6=31
//    return 0;
//}

//typedef Used to alias data types ( Is to change the name )
#include<stdio.h>
typedef double decimal;// use decimal To express double type 
int main()
{
    double number = 3.14;
    decimal number2 = 3.1415;
    printf("%lf\n", number2);
    return 0;
}

//union Type of community  ; volatile	 Explain that variables can be implicitly changed during program execution     Let's not talk about these two first 
// Thank you for your company all the way , A general summary C