a++与++a、a--与--a的区别

#include <stdio.h>
 
int main()
{
   int c;
   int a = 10;
   c = a++; 
   printf("先赋值后运算：\n");
   printf("%d\n", c ); //10
   printf("%d\n", a ); //11
   a = 10;
   c = a--; 
   printf("%d\n", c ); //10
   printf("%d\n", a ); //9
 
   printf("先运算后赋值：\n");
   a = 10;
   c = ++a; 
   printf("%d\n", c ); //11
   printf("%d\n", a ); //11
   a = 10;
   c = --a; 
   printf("%d\n", c ); //9
   printf("%d\n", a ); //9
 
}