ios - Collection <__NSArrayM: 0x7fa1f2711910> was mutated while being enumerated -

there number of questions similar title none them of helped me.

but can relate solution of 'nsgenericexception', reason: collection <__nsarraym: 0x7fabb400> mutated while being enumerated question question. because termination happening when i'm adding,removing string object array.

error :

terminating app due uncaught exception 'nsgenericexception', reason: '*** collection <__nsarraym: 0x7fa1f2711910> mutated while being enumerated.'

first throw call stack:

(  0   corefoundation                      0x00000001087b8c65 __exceptionpreprocess + 165 1   libobjc.a.dylib                     0x0000000108422bb7 objc_exception_throw + 45 2   corefoundation                      0x00000001087b85c4 __nsfastenumerationmutationhandler + 132 3                                       0x0000000107e24cf5 -[professionalregsecond tableview:diddeselectrowatindexpath:] + 773 4   uikit                               0x0000000109759d71 -[uitableview _deselectrowatindexpath:animated:notifydelegate:] + 347 5   uikit                               0x000000010974deea -[uitableview _userselectrowatpendingselectionindexpath:] + 187 6   uikit                               0x000000010968062c _applyblocktocfarraycopiedtostack + 314 7   uikit                               0x00000001096804a6 _aftercacommithandler + 533 8   corefoundation                      0x00000001086ebca7 __cfrunloop_is_calling_out_to_an_observer_callback_function__ + 23 9   corefoundation                      0x00000001086ebc00 __cfrunloopdoobservers + 368 10  corefoundation                      0x00000001086e1a33 __cfrunlooprun + 1123 11  corefoundation                      0x00000001086e1366 cfrunlooprunspecific + 470 12  graphicsservices                    0x000000010d6c8a3e gseventrunmodal + 161 13  uikit                               0x000000010965c900 uiapplicationmain + 1282 14                                      0x0000000107de14cf main + 111 15  libdyld.dylib                       0x000000010b585145 start + 1 ) 

libc++abi.dylib: terminating uncaught exception of type nsexception

what i'm trying :

i need array in such way when select cell want add object array & when i'm deselecting row want remove row array result array selected entries. how ?

here code

@implementation professional      {          nsmutablearray *updatedlocalityarray; // alloc,init did in viewdidload          nsstring *tocheck;     }  - (void)tableview:(uitableview *)tableview didselectrowatindexpath:(nsindexpath *)indexpath     {          uitableviewcell *tableviewcell = [tableview cellforrowatindexpath:indexpath];          nslog(@"%@",tableviewcell.textlabel.text);          tocheck = tableviewcell.textlabel.text;         [updatedlocalityarray addobject:tocheck];         nslog(@"%@ *****", updatedlocalityarray);     }    - (void)tableview:(uitableview *)tableview diddeselectrowatindexpath:(nsindexpath *)indexpath     {          uitableviewcell *tableviewcell = [tableview cellforrowatindexpath:indexpath];            nslog(@"%@",tableviewcell.textlabel.text);          (nsstring *test in updatedlocalityarray)         {             if ([test isequaltostring:tableviewcell.textlabel.text])             {                  [updatedlocalityarray removeobject:test];                 nslog(@"%@ *****", updatedlocalityarray);              }          }      } 

you cannot delete items nsmutablearray while iterating it.

there several solutions this:

• iterate copy of array

or

• use index-based for loop instead of for each syntax.

not copying array saves allocation , few cpu cycles:

for (int = updatedlocalityarray.count-1 ; >= 0 ; i--) {     nsstring *test = updatedlocalityarray[i];     if ([test isequaltostring:tableviewcell.textlabel.text])     {         [updatedlocalityarray removeobjectatindex:i];         nslog(@"%@ *****", updatedlocalityarray);     } }