java - BlueJ 找不到变量

Question

我正在尝试设置第一次战斗，但在第 24 行，BlueJ 告诉我变量 firsthitpoints 不可见，无法执行。

如果有人能告诉我这段代码有什么问题，我将不胜感激

  if (characterquality == "Slayer"){
        int HP = 150;
        int Attack = 75;
        int Defense = 50;
        int MP = 20;
        int EXP = 0;
        int Gold = 50;

       boolean firstbattle = true;
       while (firstbattle){
          int firstbattlehealth = HP;
          int firstbattleattack = Attack;
          int firstbattledefense = Defense;
          int firstbattleMP = MP;
          int firstbattleEXP = EXP;
          int firstbattlegold = Gold;

          int firstattack = (int) Math.ceil(Math.random() * 6);
          int firstdefense = (int) Math.ceil(Math.random() * 6);

          int firstenemyattack = (int) Math.ceil(Math.random() * 6);
          int firstenemydefense = (int) Math.ceil(Math.random() * 6);

          int firstenemyhealth = (int) Math.ceil(Math.random() * 50);

          int firstenemyhitpoints = (int) Math.ceil(Math.random() * 25);
          boolean firstkill = true;
          while (firstkill) {
              if (firstattack > firstenemydefense){
                  int firsthitpoints = (int) Math.ceil(Math.random() * firstbattleattack);

              }
              int firstenemynewhealth = firstenemyhealth - firsthitpoints;

              if (firstenemynewhealth <= 0){
                  firstkill = false;
              }
              if (firstattack <= firstenemydefense){
                 System.out.println("Attack failed!");
              }
              if (firstenemyattack > firstdefense){
                  int firstenemyhitpointattack = (int) Math.ceil(Math.random() * firstenemyhitpoints);
                  System.out.println("The enemy did " + firstenemyhitpointattack + " damage to you. You have " + firstbattlehealth + " health remaining.");
               }
              if (firstenemyattack <= firstdefense){
                  System.out.println("Enemy attack missed!");
              }
          }
          int firstenemynewhealth = firstenemynewhealth;
          if (firstenemynewhealth <= 0){
              firstbattle = false;
           }
       }
    }

Answer 1

您在前面的 if block 中定义变量，将其移到 block 外并为其指定初始值。比如，

boolean firstkill = true;
int firsthitpoints = 0; // <-- declare and initialize.
while (firstkill) {
    if (firstattack > firstenemydefense){
        firsthitpoints = Math.ceil(Math.random() * firstbattleattack);
    }
    int firstenemynewhealth = firstenemyhealth - firsthitpoints;
    // ...

此外，不是直接针对您的问题，请不要将 String 相等性与 ==.

if (characterquality == "Slayer"){

应该是

if (characterquality.equals("Slayer")) {

也许它适用于您的情况，但这只是测试引用相等性(而不是值相等性)。另请参阅How do I compare strings in Java?

最后，执行比较指令需要成本¹。您应该使用 else block ，而不是将逻辑反转与多个 if 进行比较。比如，

if (firstenemyattack > firstdefense) { 
    int firstenemyhitpointattack = (int) Math.ceil(Math.random() 
            * firstenemyhitpoints);
    // Presumably, firstbattlehealth -= firstenemyhitpointattack here?
    System.out.println("The enemy did " + firstenemyhitpointattack 
            + " damage to you. You have " + firstbattlehealth 
            + " health remaining.");
} else { // <-- An "else" block, firstenemyattack <= firstdefense
    System.out.println("Enemy attack missed!");
}

^{1_{尽管在现代环境中很小。}}