自增自减

int b=8;
int c=0;
c=++b;
cout<<"c="<<c<<endl;
cout<<"b="<<b<<endl;
结果为：c=9；b=9；
int b=8;
int c=0;
c=b++;
cout<<"c="<<c<<endl;
cout<<"b="<<b<<endl;
结果为：c=8；b=9；
int b=8;
int c=0;
c=--b;
cout<<"c="<<c<<endl;
cout<<"b="<<b<<endl;
结果为：c=7；b=7；
int b=8;
int c=0;
c=b--;
cout<<"c="<<c<<endl;
cout<<"b="<<b<<endl;
结果为：c=8；b=7；