ios - for循环疯狂

Question

好的。我在这里疯了。我有一个 for 循环，它没有在应该停止的时候停止。

我正在创建一个骰子游戏，并且骰子的数量经常变化，所以我只有一个 for 循环根据在任何给定的掷骰中应该有多少个骰子来生成骰子。这是循环:

for (int x = 0; x < numDice; x++) {
    int dieNum = (arc4random() % 6) + 1;
    SKSpriteNode *die;

    if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
        die = [SKSpriteNode spriteNodeWithImageNamed:[NSString stringWithFormat:@"dice-%i", dieNum]];
    } else if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {
        die = [SKSpriteNode spriteNodeWithImageNamed:[NSString stringWithFormat:@"dice-%i_ipad", dieNum]];
    }

    die.name = @"die";
    die.userData = [NSMutableDictionary dictionaryWithObject:@"YES" forKey:@"Rollable"];
    [die.userData setObject:[NSString stringWithFormat:@"%i",dieNum] forKey:@"Die Number"];
    [die.userData setObject:[NSString stringWithFormat:@"%i", rollNum] forKey:@"Roll Number"];
    [die.userData setObject:@"YES" forKey:@"Movable"];
    die.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:die.size];
    die.physicsBody.affectedByGravity = NO;
    die.physicsBody.categoryBitMask = dieCategory;
    die.physicsBody.collisionBitMask = dieCategory;

    int rotation = (arc4random() % 360) + 1;
    die.zRotation = radians(rotation);
    int x = (arc4random() % (int)self.frame.size.width) + (die.size.width / sinf(90.0));
    int y = (arc4random() % (int)self.frame.size.height) + (die.size.height / sinf(90.0));
    if (x < 1.75 * (die.size.width / sinf(90.0))) {
        x = 1.75 * (die.size.width / sinf(90.0));
    }
    if (y < (die.size.height / sinf(90.0))) {
        y = (die.size.height / sinf(90.0));
    }
    if (x > self.frame.size.width - (die.size.width / sinf(90.0))) {
        x = self.frame.size.width - (die.size.width / sinf(90.0));
    }
    if (y > self.frame.size.height - (die.size.height / sinf(90.0))) {
        y = self.frame.size.height - (die.size.height / sinf(90.0));
    }
    die.position = CGPointMake(x, y);
    [self addChild:die];
}

现在我有一个 NSLog 在执行循环之前输出 numDice 变量，并且 numDice 变量在我的每一个测试中都是正确的。但出于某种原因，for 循环在某个测试期间生成了随机数量的额外骰子。所以我放了一个 NSLog 输出 x 值并看到了一些有趣的东西。循环后日志会说这样的话:

2013-12-04 19:50:03.334 DiceMania[21611:60b] numDice: 6
2013-12-04 19:50:03.338 DiceMania[21611:60b] x: 0
2013-12-04 19:50:03.338 DiceMania[21611:60b] x: 1
2013-12-04 19:50:03.341 DiceMania[21611:60b] x: 2
2013-12-04 19:50:03.346 DiceMania[21611:60b] x: 3
2013-12-04 19:50:03.350 DiceMania[21611:60b] x: 4
2013-12-04 19:50:03.352 DiceMania[21611:60b] x: 5
2013-12-04 19:50:03.359 DiceMania[21611:60b] x: 0
2013-12-04 19:50:03.363 DiceMania[21611:60b] x: 1

到底为什么循环会将 x 重置为 0，然后进行更多次随机数迭代？ (我注意到 x 已经超过预期的 1 到 6 次迭代。

Answer 1

您正在使用 x 迭代循环，并将其用于循环的主体。拆分变量，使它们不会相互干扰，这样应该没问题。