incompatible pointer types
场景：incompatible pointer types assigning to 'nsmutablearray ' from '
incompatible pointer types assigning to 'nsmutablearray ' from 'nsarray '
incompatible pointer types assigning to 'nsmutablearray ' from 'nsarray '
这是因为NSMutableArray和NSArray不是同一个类型造成的.
解决方法
// NSArray --> NSMutableArray
NSMutableArray *myMutableArray = [myArray mutableCopy];
// NSMutableArray --> NSArray
NSArray *myArray = [myMutableArray copy];