Java 尝试根据用户输入使用具有不同参数的 switch 语句创建对象

Question

所以我正在使用 Java 制作一个文字冒险 RPG，我想使用一个 switch 语句来获取用户的下一个输入并创建我的 class、FTAWeapon 的实例, 根据用户的输入使用不同的参数。

例如，如果用户输入“1”，我想创建一个名为 weapon 的 FTAWeapon 实例，参数为 (1, 6, 1, 5, 8, .75)。

但是如果用户改为输入“2”，我想创建一个 FTAWeapon 实例，仍然命名为 weapon，参数为 (2, 24, 3, 7, 15, .65)。

但是，我得到这个错误：

错误：变量 weapon 已经在方法 main(String[]) 中定义

此错误出现 4 次，在第一次创建对象实例之后的所有尝试中。

这是给我问题的代码：

switch(kb.next())
           {
              case "1":
                 System.out.println("\n\n*.44 Magnum Revolver added to inventory*");
                 FTAWeapon weapon = new FTAWeapon(1, 6, 1, 5, 8, .75);
                 break;

              case "2":
                 System.out.println("\n\n*Assault Rifle added to inventory*");
                 FTAWeapon weapon = new FTAWeapon(2, 24, 3, 7, 15, .65);
                 break;

              case "3":
                 System.out.println("\n\n*Laser Pistol added to inventory*");
                 FTAWeapon weapon = new FTAWeapon(3, 30, 1, 2, 6, .85);
                 break;

              case "4":
                 System.out.println("\n\n*Caravan Shotgun added to inventory*");
                 FTAWeapon weapon = new FTAWeapon(4, 14, 7, 3, 20, .50);
                 break;

              case "5":
                 System.out.println("\n\n*Plasma Rifle added to inventory*");
                 FTAWeapon weapon = new FTAWeapon(5, 24, 1, 5, 10, .70);
                 break;
           }

Answer 1

FTAWeapon weapon = null; // Declaration outside the switch statement
switch(kb.next())
{
          case "1":
             System.out.println("\n\n*.44 Magnum Revolver added to inventory*");
             weapon = new FTAWeapon(1, 6, 1, 5, 8, .75);
             break;

          case "2":
             System.out.println("\n\n*Assault Rifle added to inventory*");
             weapon = new FTAWeapon(2, 24, 3, 7, 15, .65);
             break;

          case "3":
             System.out.println("\n\n*Laser Pistol added to inventory*");
             weapon = new FTAWeapon(3, 30, 1, 2, 6, .85);
             break;

          case "4":
             System.out.println("\n\n*Caravan Shotgun added to inventory*");
             weapon = new FTAWeapon(4, 14, 7, 3, 20, .50);
             break;

          case "5":
             System.out.println("\n\n*Plasma Rifle added to inventory*");
             weapon = new FTAWeapon(5, 24, 1, 5, 10, .70);
             break;
}

每个 case 子句中的变量范围对应于整个 switch 语句。

Java 尝试根据用户输入使用具有不同参数的 switch 语句创建对象

Java trying to create an object using switch statement with different parameters based on user input

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