How does an ionic bond look in a chemical equation?

I get the difference between an ionic bond and a covalent bond, but how do I know which is which in a molecular expression? For instance H-C indicates a covenant bond, and H=C represents a double covalent bond. What would indicate an ionic bond? These expressions are pretty self explanatory, just like H2O, but when I get into larger and more complicated molecules I can't help but get to wondering. Thanks.