Fix collection <__NSArrayM:0xb550c30> was mutated while being enumerated

When the program appears this prompt, because you side of the convenience of the array, but also modify the contents of the array, resulting in a crash, the online method is as follows:

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nsmutablearray  *  arraytemp = xxx;  nsarray  * array = [ nsarray  arraywitharray: arraytemp] ;  for   ( Nsdictionary  * dic in array)  {     if   (condition) {        [arraytemp removeobject:dic];     } }

This method is to define an identical array, to facilitate array A and then manipulate array B

Today we finally found a faster way to delete the contents of the array and modify the contents of the array:

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NSMutableArray*tempArray = [[NSMutableArrayalloc]initWithObjects:@"12",@"23",@"34",@"45",@"56", nil];[tempArray enumerateObjectsUsingBlock:^(idobj, NSUIntegeridx, BOOL*stop) {if([obj isEqualToString:@"34"]) {*stop = YES;if(*stop == YES) {[tempArray replaceObjectAtIndex:idx withObject:@"3333333"];}}if(*stop) {NSLog(@"array is %@",tempArray);}}];

Using block to operate, according to the information, found block convenience than for convenience of about 20% faster, this principle is this:

After a qualifying condition is found, the traversal is paused and the contents of the array are modified

This method is very simple.

Fix collection <__NSArrayM:0xb550c30> was mutated while being enumerated