question for any C++ progammers

> > > []$ cd ~/C++assignments
> > > [C++assignments]$ g++ Assn2.cpp -oexp1.o
> > > [C++assignments]$ dir
> > > Assn2.cpp      Currency2-1.o      Currencycalc2-2.cpp
> Currencycalc3.cpp
> > > Assn2.cpp~     Currency2-2.o      Currencycalc2-2.cpp~  exp1.o
> > > Currency1.cpp  Currencycalc2-1.cpp   Currencycalc2.cpp
> > > Currency1.o    Currencycalc2-1.cpp~  Currencycalc2.cpp~
> > > [C++assignments]$ exp1.o
> > > bash: exp1.o: command not found
> > > [C++assignments]$