Question

我一直试图将这些结果暂时解决..我似乎无法弄明白。任何人都知道如何做到这一点？

我正在尝试从数组的开头到结尾，按顺序将两个对象相互比较。

Tilo的解决方案：

        for (int i=1; i<[tempRightArray count]; i++) {
            UIImageView* letterA = [tempRightArray objectAtIndex:i-1];
            UIImageView* letterB = [tempRightArray objectAtIndex:i];

            NSLog(@"LetterA: %@",letterA);
            NSLog(@"LetterB: %@",letterB);

            //Distance between right side of Touched piece and Left side of new piece == Touch on Right
            CGPoint midPointRightSidePiece = CGPointMake(CGRectGetMaxX(letterA.frame), CGRectGetMidY(letterA.frame));
            CGPoint midPointLeftSidepiece = CGPointMake(CGRectGetMinX(letterB.frame), CGRectGetMidY(letterB.frame));
            CGFloat distance = DistanceBetweenTwoPoints(midPointLeftSidepiece, midPointRightSidePiece);

            NSLog(@"Distance: %f",distance);

        }

更新了Pauls块解决方案：

    [tempRightArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

        if (idx > 0) {

            UIImageView *letterB = (UIImageView*)obj;

            id obj2 = [tempRightArray objectAtIndex:--idx]; // idx is the index of obj again given to you by the block args

            UIImageView *letterA = (UIImageView*)obj2;

            NSLog(@"LetterA: %@",letterA);
            NSLog(@"LetterB: %@",letterB);

            //Distance between right side of Touched piece and Left side of new piece == Touch on Right
            CGPoint midPointRightSidePiece = CGPointMake(CGRectGetMaxX(letterA.frame), CGRectGetMidY(letterA.frame));
            CGPoint midPointLeftSidepiece = CGPointMake(CGRectGetMinX(letterB.frame), CGRectGetMidY(letterB.frame));
            CGFloat distance = DistanceBetweenTwoPoints(midPointLeftSidepiece, midPointRightSidePiece);

            NSLog(@"Distance: %f",distance);

        }

    }];

Answer 1

for (int i=1; i<[myArray count]; i++) {
  id obj1 = [myArray objectAtIndex:i-1];
  id obj2 = [myArray objectAtIndex:i];

  [self compare:obj1 to:obj2];
}

Answer 2

这样的事情怎么样？

  NSArray *array = [NSArray arrayWithObjects:@"a", @"b", @"b", @"c", @"d", nil];

  [array enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

    if (idx > 0) {
      // obj  = the current element in the array. Given to you by the block args
      id obj2 = [array objectAtIndex:--idx]; // idx is the index of obj again given to you by the block args

      // Do whatever comparison you want between obj and obj2
      // ...
    }

  }];

不要被语法吓到它非常简单。当前对象为obj，数组中该对象的索引为idx。

Answer 3

启动for循环，索引为1。当索引大于或等于数组计数时停止。比较index和index - 1处的项目;

Answer 4

for (i = 0; i < array_count - 1; i++) {
   x = array[i];
   y = array[i + 1];
   /* do something with x and y */
}

array是数组，array_count是array的长度，x和y被声明为与存储的元素相同的类型array。这是你要的吗？

Answer 5

不要忘记Objective-C是C的超集。你可以在C中做任何事情，你仍然可以在Obj-C中做。

您可能不知道comma operator。您可以在for(;;)循环的每个子句中执行多个操作。

NSUInteger limit, i, j;

for(limit = [array count], i = 0, j = 1; j <= limit; i++, j++)
  {
  //  i and j will increment until j hits the limit.   
  // do whatever you want with [array objectAtIndex:i] and [array objectAtIndex:j] in here.
  }

对于循环，它将给我索引的对象：0,1然后1,2然后2,3然后3,4遵循此模式直到数组计数？

5 个答案: