Can you use the iPhone 5 charger on the Galaxy s4?

I forgot my charger but my friend has the iphone 5 and I checked the poor and they look like they would fit but I'm scared to try it and mrs up the battery and what not

No. Its not compatible.

Just do it. Its not going to mess it up.

Nope, its not compatible at all. Maybe you can just use the plug in that has the usb plug but not the maun wire. Especially iphone 5 use micro charger and samsung use different one