"-" or "_" to sperate words in a URL

I have a shopping cart site and the cart program has the option to create "static" pages for my products. I can select the hyphen (-) or the underscore (_) for spaces in the URL that is generated by my product's name:

For example:

Men's Size 11 Shoes

can become:

mens-size-11-shoes.html

or

mens_size_11_shoes.html


So my question is, dashes or underscores? Do search engines care?

 

Dashes are preferred. If you use underscore, search engines will consider 'mens_size_11_shoes' as 1 word. Whereas, if you use 'mens-size-11-shoes' (dashes in URL), that page can be returned for the searches mens, shoes, and even 'mens size'.

 

Dashes are prefered, but Google can still see individual words joined with an underscore just fine.

 

Dashes or Plus will yield higher results try search it on google.

keyword1+keyword2
keyword1-keyword2
keyword1_keyword2

see which one more results.

 

There are already dozens of threads discussing this question ad nauseam. Use the search tool to find them and learn more than you'd like to know.

 

Dashes are preferred to use because it serves as a localized EXACT operation, while the underscores are considered as word separators....

 

That's completely wrong.

 

The one that is acceptable by spiders is the dash/hypen (-).