Simple syntax question: "does this page have children?"

Just a quick question for those who know PHP better than I do (which would mean “more than not at all”).

What I want to do is to show something in the sidebar for pages that have children, and for pages that don’t have children, show nothing.

So I can do this by checking if get_page_children() [for the page you’re on] is false, right?

Can anyone quickly dash off that if/else statement (or let me know if my above assumption is incorrect)?

That would be helpful. Otherwise I can continue to muddle through. Thanks!