我們可以在if-else的情況下使用（id）嗎？

Question

我以cocos2d的方式編寫了我的代碼。

id actionTo = [CCFadeOut actionWithDuration:4.0f]; 
id actionTo0 = [CCSequence actionWithDuration:2.0f]; 
if (m < enemyNumber) 
    id actionTo1 = [CCCallFunc actionWithTarget:self selector:@selector(goToNextScene)]; 
else 
    id actionTo1 = [CCCallFunc actionWithTarget:self selector:@selector(goToEndScene)]; 
id actionSeq = [CCSequence actions:actionTo, actionTo0, actionTo1, nil]; 
[targetE runAction: [CCSequence actions:actionSeq, nil]]; 

error: expected expression before 'id' 

我得到了上述錯誤。我們不應該在if條件下使用（id）嗎？ 我想通過使用if- else條件來調用兩個選擇器。 我該怎麼做？ 謝謝。

Answer 1

所以，很簡單寫

id actionTo1 = [CCCallFunc actionWithTarget:self selector: 
       (m<energyNumber ? @selector(goToNextScene) : @selector(goToEndScene))]; 

Answer 2

你不能在那個地方聲明新的變量。你應該做的是，如果條件並有其值設置之前聲明的變量actionTo1：

... 
id actionTo1 = nil; 
if (m < enemyNumber) 
    actionTo1 = [CCCallFunc actionWithTarget:self selector:@selector(goToNextScene)]; 
else 
    actionTo1 = [CCCallFunc actionWithTarget:self selector:@selector(goToEndScene)]; 
...