ios - a faster way to mutate an Array of NSMutableDictionaries -

based on fact cannot edit mutable collections while enumerating them, best solution come edit array of nsmutabledictionaries:

__block nsmutabledictionary *tempdict = [nsmutabledictionary dictionarywithcapacity:1]; __block nsuinteger idx; [_myarray enumerateobjectsusingblock:^(nsmutabledictionary* obj,                                                          nsuinteger indx, bool *stop) {     if (// condition met) {         tempdict = [obj mutablecopy];         idx = indx;     } }];  [tempdict setobject:[nsnumber numberwithint:thisqueryresults] forkey:@"resultsnum"]; [_myarray replaceobjectatindex:idx withobject:rowselected]; 

this seems way complicated (even language obj-c).. , since it's involving 2 data types (nsmutablearray , nsmutabledictionary), doesn't seem can cleanly put them category.. advice?

update: 1 comment asked why create mutablecopy (as opposed copy.. since it's copying mutable object)..

suppose used copy.. if put break on tempdict get:

// tempdict = [obj copy] po tempdict $0 = 0x0b28cc10 <__nsarrayi 0xb28cc10>( 1 )  // tempdict = [obj mutablecopy] po tempdict $0 = 0x0b28cc10 <__nsarraym 0xb28cc10>( //notice m in __nsarraym opposed above 1 ) 

in case of copy.. if follow line this: [tempdict setobject:[nsnumber numberwithint:thisqueryresults] forkey:@"resultsnum"];

i error:

[__nsdictionaryi setobject:forkey:]: unrecognized selector sent instance 0xb245100 

i same above error this code:

for (nsuinteger idx = 0; idx < [_mymutablearray count]; idx++) {     nsmutabledictionary* mymutabledict = _mymutablearray[idx];     [mymutabledict setobject:obj forkey:key];         } 

update 2: origin of problem instantiating non mutable arrays , dictionaries.. i'm new whole new obj-c literals, didn't know create nsmutablearray , nsdictionary, gotta this, respectively:

[@[..] mutablecopy] [@{..} mutablecopy] 

so in case, don't quite follow why call tempdict = [obj mutablecopy]; when conditions write dictionary writable.

you can use several tricks. using

for (nsuinteger idx = 0; idx < _myarray.count: idx++_ {    nsmutabledictionary *obj = _myarray[idx];    // modify } 

for nsdictionaries can allkeys , iterate on copy. bit slower using fast enumeration, still faster doing workarounds boxing integers replace later :)