ios - How to delete a bunch of NSData in NSUserDefault -

i stored setting peripheral connected ios device, want add button user delete peripheral, means must delete setting related peripheral.

the store simple using nsdata:

nsuserdefaults *defaults = [nsuserdefaults standarduserdefaults]; nsdata *encodedobject = [nskeyedarchiver archiveddatawithrootobject:self.appdelegate.defaultbtserver.selectperipheralinfo]; [defaults setobject:encodedobject forkey:self.appdelegate.defaultbtserver.selectperipheralinfo.uuid]; [defaults synchronize]; 

but how delete setting related selectperipheralinfo.uuid? found

nsuserdefaults *defaults = [nsuserdefaults standarduserdefaults]; [defaults removeobjectforkey:application.defaultbtserver.selectperipheralinfo.uuid]; 

cannot work.

it looks might not using same key add , remove data. add, used:

self.appdelegate.defaultbtserver.selectperipheralinfo.uuid 

but remove data used:

application.defaultbtserver.selectperipheralinfo.uuid 

if values of expressions aren't same, won't able remove data added because, obviously, key wrong. so, check that.

also, make sure call [defaults synchronize] after removing update defaults in storage.