001

iostream
cin
cout
cerr
clog
'<<'插入符
'>>'提取符
dec
hex
oct
endl
setprecision(int)
setw(int)
setiosflags()
resetiosflags()
cout<<fixed<setprecision(2)<1.23456<endl;
ofstream
ifstream
fstream
fin
fin.bad()
fin.ignore()
fin.close()
fout.bad()
fout.close()