Can you charge an iPad with an iPhone charger?

My iPhone charger was plugged into the outlet for around a day (without anything attached to it or being charged with it, though). However, my sister plugged her iPad into the phone charger around dinnertime because she couldn't find her iPad charger, but then took it out like 15 minutes later because she didn't know if you could do that and she was paranoid that she broke my charger. I thought it was fine at the time and plugged my phone into the charger right after she took the iPad out. But now that I think about it I kind of want to double check:

- Can you charge an iPad with an iPhone charger?
- Does doing so damage the charger?
- Is my phone's battery life somehow damaged now because I plugged my phone in to charge after?

I've been noticing that recently my phone's started draining kind of quickly… Although that might just be because the auto-brightness has been off lately. I don't know, though.It'd be awesome if I could get some answers to these questions, though

Yes, you can charge the ipad with the iPhone charger. You can charge the ipad with any charger as long it's an iPhone or iPod, ipad charger

Old ipads and old iphones I think no… But the new standard plugin they now use (iphone 5 etc) should be the same for all.