how can i delete all contacts from my iphone?

it's simple brother😉 :

first download app from app store called contactsXL

this app allow u to selecte many names in same time

after finish download the app go to ur contact u can find arrow in the upper right corner press it then select delete contact then it will appear, press the under bottum which said select all then remove it all.

i hope it will help u 🙂

Thanks very much for this tip. I had been unable to get my contacts to synch with iPhone, and I couldn't delete them from the phone to allow iCloud to work. After installing this app, I was able to clear out 'stuck' contacts and synch now works fine. Bravo!