So, the question is how Google considers this ? If I search restaurants in new york to which type the preference is given.
Which will have higher ranking ?
( 7 months ago )
They'll all probably have the exact same ranking, no matter what. More important: Don't screw up real users when doing SEO.
You might do everything for nothing (i.e. no or no significant change).
Talking URLs are for users to know what content they can expect. They're not for search engines. if you optimize your overall appearance just for a high search engine ranking, even if people won't want your page contents, you might profit off this at first, but they won't return.
When using path separators (/) in your URL, expect users to use these. If they can't use them, you generate a bad user experience and they might rather leave your page and look elsewhere for what they're using.
Similar reason: Only use path separators if there's a real reason for them, for example, if they're some logical grouping. In your example above, the second and third variation would be bad, because the separation doesn't make any sense at all.
How I'd do it:
If we're talking about a single blog post or something like that, don't use any path separators at all: example.com/restaurants-in-new-york. That's it. Don't touch it or change it.
If we're talking about some listing, you can provide the user hints on how to quickly change their actual query or results. Here I'd use something like example.com/restaurants/new-york.
I hope you understand what my intention here is. Let's assume the user now wants to know what restaurants are there in Chicago. He won't have to navigate or look for some link. He could just edit the URL: example.com/restaurants/chicago. There he is. Good user experience. If you look at your third example, you've got that unnecessary filler in: It doesn't serve any purpose at all (hint: Google most likely ignores such fillers anyway).
TL;DR: Don't optimize for Google or any other search engine. Optimize for your users. Modern search engines are built to see pages similar to users. You can have the prettiest key words in your URLs, yet they won't help you at all if they're strictly confusing or obviously just made for SEO.