得到錯誤 - 無法找到或加載主類makingachange.Main在NetBeans

Question

我得到這個錯誤 - 無法找到或加載makingachange.Main每當我試圖運行程序，我不明白爲什麼它是主類向我展示這個錯誤，因爲我真的是Java的新手。是否有人可以幫助我在試圖解決這一問題：

import java.util.Scanner; 
package makingachange; 

public class Main { 
    private int[] denom; 
    Main(int[] denom) { 
     this.denom = denom; 
    } 
    void giveChange(int changeRs) { 
     System.out.println("\nChange for " + changeRs + " in Rs " + ":"); 
     for(int i = 0; i < denom.length; ++i) { int nb = changeRs/denom[i]; if(nb > 0) 
       System.out.println(nb + " " + denom[i]); 
      changeRs %= denom[i]; 
     } 
    } 
    public static void main(String[] args) { 
       int[] Rs = {100,50,20,10,5,1}; 
       Scanner input=new Scanner(System.in); 
       System.out.println("Enter the purchase amount : "); 
       int purchaseAmount=input.nextInt(); 
       System.out.println("Enter the amount given by customer : "); 
       int AmountGivenByCusto=input.nextInt(); 
       if(AmountGivenByCusto<purchaseAmount){ 
        System.out.println("Sorry! you paid less than purchase amount! "); 
       }else 
{ 
       int result=AmountGivenByCusto-purchaseAmount; 
     Main change1 = new Main(Rs); 
     change1.giveChange(result); 
       } 
    } 
} 

Answer 1

首先出現的是一個錯誤

package的說法應該是第一條語句所以它應該是這個

package makingachange; 
import java.util.Scanner; 

，那麼你必須首先生成包

javac -d . Main.java 

java makingchange/Main.java 

-d mean創建包

.意味着生成當前目錄的使用路徑，才能生成包

Answer 2

確保包定義的java.util.Scanner導入前寫的。仔細檢查工作區中的軟件包是否與您在課堂中定義的軟件包名稱完全相同（因此在這種情況下爲：makingachange）。

以下代碼適用於我。

package makingachange; 
import java.util.Scanner; 

public class Main { 
    private int[] denom; 

    Main(int[] denom) { 
     this.denom = denom; 
    } 

    void giveChange(int changeRs) { 
     System.out.println("\nChange for " + changeRs + " in Rs " + ":"); 
     for (int i = 0; i < denom.length; ++i) { 
      int nb = changeRs/denom[i]; 
      if (nb > 0) 
       System.out.println(nb + " " + denom[i]); 
      changeRs %= denom[i]; 
     } 
    } 

    public static void main(String[] args) { 
     int[] Rs = { 100, 50, 20, 10, 5, 1 }; 
     Scanner input = new Scanner(System.in); 
     System.out.println("Enter the purchase amount : "); 
     int purchaseAmount = input.nextInt(); 
     System.out.println("Enter the amount given by customer : "); 
     int AmountGivenByCusto = input.nextInt(); 
     if (AmountGivenByCusto < purchaseAmount) { 
      System.out.println("Sorry! you paid less than purchase amount! "); 
     } else { 
      int result = AmountGivenByCusto - purchaseAmount; 
      Main change1 = new Main(Rs); 
      change1.giveChange(result); 
     } 
    } 
}