如何在Objective-C [重复]中随机移动数组的元素

Posted 2021-04-21

可能重复：canonical way to randomize an NSArray in Objective-C

假设我有一个如下数组。

shuffleArray = [[NSMutableArray alloc] initWithObjects:@"A",@"B",@"C",@"D",@"E", nil];

并且我想如下随机改变数组元素的位置：

shuffleArray = [[NSMutableArray alloc] initWithObjects:@"C",@"A",@"B",@"E",@"D", nil];

那我该怎么办？

答案

-(NSArray *)shuffleme
{

 NSMutableArray *array = [NSMutableArray arrayWithCapacity:[self count]];

 NSMutableArray *array1 = [self mutableCopy];
 while ([array1 count] > 0)
 {
  int temp = arc4random() % [array1 count];
  id objectToMove = [array1 objectAtIndex:temp];
  [array addObject:objectToMove];
  [array1 removeObjectAtIndex:temp];
 }

   [array1 release];
   return array;
}

希望，对您有帮助。.>

另一答案

-(void)changeObjectAtIndex:(int)index1 index2:(int)index2 array:(NSMutableArray *)array
{
     id objectAtIndex1=[array objectAtIndex:index1];
     [array insertObject:[array objectAtIndex:index2] atIndex:index1];
     [array insertObject:id atIndex:index2];
}