reason: ‘*** Collection was mutated while being enumerated

2015-09-22 16:45:42.229 ViewTest[2638:c07] *** Terminating app due to uncaught exception ‘NSGenericException’, reason: ‘*** Collection <__NSArrayM: 0xb550c30> was mutated while being enumerated.’

当程序出现这个提示的时候，是因为你一边便利数组，又同时修改这个数组里面的内容，导致崩溃，网上的方法如下：

NSMutableArray * arrayTemp = xxx;
NSArray * array = [NSArray arrayWithArray: arrayTemp];
for (NSDictionary * dic in array) {
   if (condition){
      [arrayTemp removeObject:dic];
   }
}

这种方法就是在定义一个一模一样的数组，遍历数组A然后操作数组B