iphone - find special keys in UserDefaults by "substringToIndex" -

i'm grouping userdefault keys specific prefixes.

e.g.

[nsuserdefaults standarduserdefaults] setinteger: 1 forkey: @"prefix1_sometext_key"] [nsuserdefaults standarduserdefaults] setinteger: 2 forkey: @"prefix2_sometext_key"] [nsuserdefaults standarduserdefaults] setinteger: 3 forkey: @"prefix4_sometext_key"] //..... 

now, i'd find keys, start e.g. "prefix", , load them array. there way doing (programmatically)?

you use underlying nsdictionary find suitable keys:

nsstring *myprefix = @"prefix"; nsuserdefaults *defaults = [nsuserdefaults standarduserdefaults]; nsdictionary *dict = [defaults dictionaryrepresentation]; nsmutablearray *keyswithprefix = [nsmutablearray array] (nsstring *key in dict.keyenumerator) {   if ([key hasprefix: myprefix]) {     [keyswithprefix addobject: key];   } } // keyswithprefix contains matching keys 

update debugging reasons add log see keys being dropped:

for (nsstring *key in dict.keyenumerator) {   if ([key hasprefix: myprefix]) {     [keyswithprefix addobject: key];   } else {     nslog(@"dropping key %@", key);   } }