i++和++i的区别

 int main()
 {
    int i=0,j=0,a,b;
   a=i++;
   b=++j;
   cout<<"i="<<i<<endl;
   cout<<"j="<<j<<endl;
    cout<<"a="<<a<<endl;
    cout<<"b="<<b<<endl;
 }

输出能看出++i和i++的区别.