How do I extract a partial attribute value?

How do I extract a partial attribute value?

Hi, I'm new to jquery. I like to ask about how do I get a partial attribute value?
My code: 
<a href="#" id="id-1">Link 1</a> <a href="#" id="id-2">Link 2</a> <a href="#" id="id-3">Link 3</a>
I like to extract link attribute value in id-x, so I'll get numeric 1 or 2 or 3.

 How do I do this? Thanks before.