My second blog - C language

         I'm glad today , That is to say 10 month 22 Write my blog on the th —— About C linguistics

        My programming goals , The fastest winter vacation from the first semester of freshman to the next semester C The foundation of language is solid , Basically finished , The foundation is not solid , The earth trembled and the mountains swayed ; Learning to program , I think we should rely more on ourselves to fight , More in b Stand and watch online classes , It mainly depends on self-taught programming and professional courses in school ; I hope that after four years of study in University , Enter Tencent , Or bytes and so on IT company

//C In language hex For hexadecimal ,oct For octal ,dec For decimal ,bin For binary
// Calculate the length of several common types of bytes
 int main()
{
     int a, b, c, d;
     a = sizeof(short);
     b = sizeof(int);
     c = sizeof(long);
     d = sizeof(long long);
     printf("%hd\n", a);
     printf("%d\n", b);
     printf("%d\n", c);
     printf("%d\n", d);

     return 0;
}
 

Common keyword classification
aunt  break  case  char  const  continue  default  do  double  else enum 

extern  float for  goto if  int  long  register  return  short  signed
sizeof  static struct  switch  typedef union  unsigned  void  volatile while  

#include<stdio.h>// The header file

int main()

{  int a = 0, b = 0;// Variable initialization

        printf(")

return 0;

}

#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
//int main()
//{
//    printf("%d\n", printf("Hello world!\n") - 1);
//
//    return 0;
//}
//static
//void test()
//{
//    static int a = 1;
//    a++;
//    printf("%d ", a);
//}
//int main()
//{
//    int i = 0;
//    
//    while (i < 10)
//    {
//        test();
//        i++;
//    }
//
//    return 0;
//}

//extern It's a keyword , Is an external symbol for reputation
// extern int g_val = 2021;
//int main()
//{
//    printf("%d", g_val);
//
//    return 0;
//}
// If not extern Go to the external symbol that you define
// be main Function cannot call this external symbol
// A global variable can be used in other files throughout the project , Because global variables have external connection properties
// When a global variable is static When decorating , The external link attribute of this variable becomes the internal link attribute
// Make this global variable can only be used inside its own source file , Other files can no longer be used
int Add(int x, int y)
{
    return x + y;
}
int main()
{
    int a, b;
    scanf("%d%d", &a, &b);
    int ret = Add(a, b);
    printf("%d", ret);

    return 0;
}