can you get arrested for shoplifting even though you did not walk out of the store with the merchandise?

The answer is yes.  In every jurisdiction I'm familiar with, merely concealing merchandise while inside the store is legally sufficient for an arrest.  

You can walk inside the store with things in your arms and it doesn't mean you're going to steal them because there were no extra baskets to put them inside would be your best excuse to not be arrested.

Of course; the crime is the intention to steal. 

You can be arrested for going equipped to steal - for example, having multiple internal (purpose made) pockets in a long coat or a backpack lined with foil to block tag detectors.  

Yes. All that's needed is they show you had the intent to shoplift. If you stuff something in your jacket or backpack, that'll often be enough. Particularly if they have you on video looking both ways before stuffing it in your backpack.

yes you can..........

Of course. You could be an accomplice.  In MY State you can be arrested based on INTENT, not on the actual act.

Of course you can.  

Oh stop the nonsense..  If you had it in your bag or coat, you were going to steal it.  Guilty.

Yes you can if you walk into the restroom with the stuff.