從 class 創建新的 object 時出現“找不到符號”錯誤？

Question

public class Monster{

public final String TOMBSTONE = "Here Lies a Dead monster";


private int health = 500;
private int attack = 20;
private int movement = 2;

public String name = "Big Monster";


public int getAttack()
{
    return attack;
}

public int getMovement()
{
    return movement;
}

public int getHealth()
{
    return health;
}

public Monster(int health, int attack, int movement)
{
    this.health = health;
    this.attack = attack;
    this.movement = movement;

}

public Monster()
{

}}


public class Frank {

public static void main(String[] args){

    Monster NewMonster = new Monster();

    NewMonster.name = "Frank";

    System.out.println(NewMonster.name + " has an attack value of " + NewMonster.getAttack());

}

}

嘗試從我的 Monster class 創建新的 object 時，出現此錯誤：

Frank.java:5: error: cannot find symbol
            Monster NewMonster = new Monster();
            ^

符號：class 怪物位置：class 弗蘭克

我對 Java 很陌生，所以很抱歉，如果這是一個簡單/容易的修復，但我研究的所有內容都沒有給我解決這個錯誤的方法。

提前感謝您的任何回復/反饋。

Answer 1

Java 的一個文件中不允許有多個公共類。 因此，您需要刪除其中一個類的公共修飾符，或者將主要方法放在公共 class 中。 我做了后者，因為沒有必要將主要方法放在單獨的 class 中來實例化您的 object。

我已經更新了你的代碼，它現在可以運行了

public class Monster{

    public static void main(String[] args) {

        Monster NewMonster = new Monster();

        NewMonster.name = "Frank";

        System.out.println(NewMonster.name + " has an attack value of 
        " + NewMonster.getAttack());
    }

    public final String TOMBSTONE = "Here Lies a Dead monster";


    private int health = 500;
    private int attack = 20;
    private int movement = 2;

    public String name = "Big Monster";


    public int getAttack() {
        return attack;
    }

    public int getMovement(){
        return movement;
    }

    public int getHealth(){
        return health;
    }

    public Monster(int health, int attack, int movement){
        this.health = health;
        this.attack = attack;
        this.movement = movement;
    }

    public Monster(){}
}

Answer 2

1 您必須只定義一個 class 一個公共，它將根據您的 java 文件名（.java）保存

2 object 引用將始終為小寫

class 怪物{

public final String TOMBSTONE = "Here Lies a Dead monster";

private int health = 500;
private int attack = 20;
private int movement = 2;

public String name = "Big Monster";

public int getAttack() {
    return attack;
}

public int getMovement() {
    return movement;
}

public int getHealth() {
    return health;
}

public Monster(int health, int attack, int movement) {
    this.health = health;
    this.attack = attack;
    this.movement = movement;

}

public Monster() {

}

} // 只有 Frank 可以是單個 java 文件中的公共 class，否則創建兩個不同的 java 類並導入。 公共 class 弗蘭克 {

公共 static 無效主（字符串 [] 參數）{

Monster newMonster = new Monster();

newMonster.name = "Frank";

System.out.println(newMonster.name + " has an attack value of " + newMonster.getAttack());

} }

Output：弗蘭克的攻擊值為20