java - 返回方法定义中的特定数组对象

Question

我需要确定 PredatorList 数组中的哪个捕食者受到的伤害最大。由于某种原因，当我尝试返回该掠食者时，Eclipse 说 - mostDamaged 无法解析为变量。

为什么会这样？

public Predator mostDamagedPredator() {
    // test if PredatorList contains predators
    if (PredatorList.length > 0){
        float difference = 0;
        for (int i = 0; i < PredatorList.length; i++) {
            if (PredatorList[i].getMaxHitPoints() - PredatorList[i].getHitPoints() > difference){
                Predator mostDamaged = PredatorList[i];
            }
        }
        return mostDamaged;  // ERROR - mostDamaged cannot be resolved to a variable
    }
    // return null if there are no predators in PredatorList
    return null;
}

Answer 1

您在 if 语句 block 内声明了 mostDamaged，因此它不在该 block 之外的范围内。

将其移到外面:

public Predator mostDamagedPredator() {
    if (PredatorList.length > 0){
        float difference = 0;
        Predator mostDamaged = null;
        for (int i = 0; i < PredatorList.length; i++) {
            if (PredatorList[i].getMaxHitPoints() - PredatorList[i].getHitPoints() > difference){
                mostDamaged = PredatorList[i];
            }
        }
        return mostDamaged; 
    }
    return null;
}

或者更好一点:

public Predator mostDamagedPredator() {
    Predator mostDamaged = null;
    if (PredatorList.length > 0){
        float difference = 0;
        for (int i = 0; i < PredatorList.length; i++) {
            if (PredatorList[i].getMaxHitPoints() - PredatorList[i].getHitPoints() > difference){
                mostDamaged = PredatorList[i];
            }
        }
    }
    return mostDamaged;
}