在iPhone的字典數組中排序浮點數據？

Question

我有字典的陣列，它是在一種格式，

resultsArray = { 

id = 1; 
name = test; 
distance = 11.5; 

id = 2; 
name = test1; 
distance = 0.5; 

id = 3; 
name = test2; 
distance = 2.5; 

id = 4; 
name = test4; 
distance = 1.5; 

}

我想使用的距離鍵和我的浮子式距離排序的數組。那麼我怎樣才能排序數組使用距離是在升序？

，所以我期待的結果是這樣，

resultsArray = { 

id = 2; 
name = test1; 
distance = 0.5; 

id = 4; 
name = test4; 
distance = 1.5; 

id = 3; 
name = test2; 
distance = 2.5; 

id = 1; 
name = test; 
distance = 11.5; 

} 

請幫助我。

謝謝！

Answer 1

NSArray *sortedArray = [resultsArray sortedArrayUsingDescriptors:[NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"distance" ascending:YES]]]; 

Answer 2

[resultArray sortUsingComparator:^NSComparisonResult(id obj1, id obj2) { 
    return [[obj1 objectForKey:@"distance"] compare:[obj2 objectForKey:@"distance"]]; 
}]; 

Answer 3

還有一個解決方案：

@interface NSDictionary(sortingByDistance) 
-(NSComparisonResult) compareByDistance:(NSDictionary*)dict; 
@end 
@implementation NSDictionary(sortingByDistance) 
-(NSComparisonResult) compareByDistance:(NSDictionary*)dict { 
    return [[self objectForKey:@"distance"] compare:[dict objectForKey:@"distance"]]; 
} 
@end 

我們排序陣列可以使用sortUsingSelector方法：

[resultArray sortUsingSelector:@selector(compareByDistance:)];