Java - 使用在if語句中創建的變量

Question

我需要使用在if語句內創建的變量。我的代碼，但是，不編譯。我只需要幫助編譯它，同時保持功能相同。

下面是代碼的片段

else if (in.equals("Monster") && in1.equals("Orc")) 
    { Players Character = new Orc(); 
    System.out.println("You have chosen "+in+" type "+in1+". Monsters in general are more attack orientated"); 
    } 
    Character.addAttack(5); 

Answer 1

爲了使它在您的if條件之外工作，您只需在之外聲明條件。

/* Declare it here */ 
Players Character = null; 

if(...) { 
/* Do Something Here */ 
} else if (in.equals("Monster") && in1.equals("Orc")) { 
    Character = new Orc(); 
    System.out.println("You have chosen " + in + " type " + 
         in1 + ". Monsters in general are more attack orientated"); 
} 

/* Now you can use it here */ 
Character.addAttack(5); 

Answer 2

你必須移動if外面聲明：

Players character = null; 
// ... 
else if (in.equals("Monster") && in1.equals("Orc")) 
{ 
    character = new Orc(); 
    System.out.println("You have chosen "+in+" type "+in1+". Monsters in general are more attack orientated"); 
} 
// TODO: check for null 
character.addAttack(5); 

一些閱讀有關變量的範圍：http://www.cs.berkeley.edu/~jrs/4/lec/08