1.++前置

#include<stdio.h>
int main()
{
  int i = 10, j = 0;

  /*i = i++;*/

  /*j = i++;*/

  j = ++i;//先对i++，再赋值给j

  printf("%d %d", i,j);i=11,b=11

}

2.++后置

#include<stdio.h>
int main()
{
  int i = 10, j = 0;
  
  j = i++;//线把i赋值给j,再对i进行++操作
  printf("%d %d", i,j);i=11,b=10
}