Question

我有一个数组如何在降序中对此进行排序下面是我需要排序的数组我该怎么做？以下是我写的代码

array(
"4.3",
"4.8",
"4.4",
"4.8",
"6.5"
) 


  NSSortDescriptor *sortDescriptor;
  sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"floats" ascending:YES];
  NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];
  [sortArray sortUsingDescriptors:sortDescriptors];
  NSLog(@"sort array %@",sortArray);

Answer 1

试试以下代码。

NSArray *arForData = @[@4.3,@4.8,@4.4,@4.8,@6.5];
NSArray *sortedArray = [arForData  sortedArrayUsingComparator:
                            ^NSComparisonResult(id obj1, id obj2){
                                //descending order
                                return [obj2 compare:obj1];
                                //ascending order
                                return [obj1 compare:obj2];
                            }];
NSLog(@"%@",sortedArray);

结果 - 降序（＆＃34; 6.5＆＃34 ;, ＆＃34; 4.8＆＃34 ;, ＆＃34; 4.8＆＃34 ;, ＆＃34; 4.4＆＃34 ;, ＆＃34; 4.3＆＃34; ）

结果 - 升序（＆＃34; 4.3＆＃34 ;, ＆＃34; 4.4＆＃34 ;, ＆＃34; 4.8＆＃34 ;, ＆＃34; 4.8＆＃34 ;, ＆＃34; 6.5＆＃34; ）

Answer 2

只需将NO传递给ascending参数：

sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"floats" ascending:NO];

Answer 3

NSArray *arr = [NSArray arrayWithObjects:@4.3,@4.8,@4.4,@4.8,@6.5,nil];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"floats" ascending:NO];
NSMutableArray *sortArray = [NSMutableArray arrayWithObject:arr];
[sortArray sortUsingDescriptors:@[sortDescriptor]];
NSLog(@"sort array %@",sortArray);

如何在ios中降序排序数组？

3 个答案: