在iPhone中的字典数组中对浮点数据进行排序？

Question

我正在使用Dictionary的数组，它的格式为

 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;

}

我想使用距离键和浮点类型中的距离对数组进行排序。那么我如何使用距离按升序对数组进行排序？

所以我期待这样的结果，

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;

}

请帮帮我。

谢谢！

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

还有一个解决方案：

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

现在要排序数组，您可以使用sortUsingSelector方法：

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