punctuation - Do exclamation and question marks always end a sentence?

It is true that exclamation and question marks end sentences in the same way a period does.

Don't do that!

Would you like to go out to eat?

However, in a more complex sentence, do exclamation and question marks replace commas? It would seem this is most common with dialog.

"Don't do that!" he said.

"Would I do that? because I don't think I would."

In a more complex sentence, do exclamation and question marks replace commas? meaning they don't end the sentence.