我可以根据Objective-C中的键对NSDictionary进行排序吗？

Question

我可以根据密钥对NSDictionary进行排序吗？

Answer 1

您可以对键进行排序，然后通过迭代来创建NSMutableArray。

NSArray *sortedKeys = [[dict allKeys] sortedArrayUsingSelector: @selector(compare:)];
NSMutableArray *sortedValues = [NSMutableArray array];
for (NSString *key in sortedKeys)
    [sortedValues addObject: [dict objectForKey: key]];

Answer 2

使用objectsForKeys:notFoundMarker:来实现

要简单得多

NSDictionary *yourDictionary;
NSArray *sortedKeys = [yourDictionary.allKeys sortedArrayUsingDescriptors:@[[NSSortDescriptor sortDescriptorWithKey:@"self" ascending:YES]]];
// As we using same keys from dictionary, we can put any non-nil value for the notFoundMarker, because it will never used
NSArray *sortedValues = [yourDictionary objectsForKeys:sortedKeys notFoundMarker:@""];