將物件移動到另一個索引

將藍色移動到陣列的開頭：

NSMutableArray *myColors = [NSMutableArray arrayWithObjects: @"Red", @"Green", @"Blue", @"Yellow", nil];

NSUInteger fromIndex = 2;
NSUInteger toIndex = 0;

id blue = [[[self.array objectAtIndex:fromIndex] retain] autorelease];
[self.array removeObjectAtIndex:fromIndex];
[self.array insertObject:blue atIndex:toIndex];

myColors 現在是 [@"Blue", @"Red", @"Green", @"Yellow"]。