常用 OC 排序方法: 

1).不可变数组

- (NSArray*)sortedArrayUsingSelector:(SEL)comparator;

- (NSArray*)sortedArrayUsingComparator:(NSComparator)cmptr;

2)可变数组

- (void)sortUsingSelector:(SEL)comparator;

- (void)sortUsingComparator:(NSComparator)cmptr;

3).字典排序

- (NSArray*)keysSortedByValueUsingComparator:(NSComparator)cmptr ;

- (NSArray*)keysSortedByValueUsingSelector:(SEL)comparator;

欢迎大家指出文中的错误！

也欢迎大家指出文中的不足！