有人可以帮我修复这段代码吗？ （Java方法）

Question

此代码是一个在屏幕上垂直显示我的名字的类，每个字母最多使用5行5列字符输入，每个字母之间有一个空行。

它运行得很好，但问题是我使用static作为字符串，我的教授说在代码中的任何地方都不应该有静态而是main。当我从字符串c中删除静态时，它会破坏代码，即使在main

中声明字符串c

public class Lab3
{

    static String c;

    public static void main(String[] args)
    {

        Lab3 classy = new Lab3();
        Scanner input = new Scanner(System.in);

        System.out.print("Which character would you like to display?");

        c = input.next();

        System.out.println("My name is Jonathan");
        classy.displayLetterJ();
        classy.displayLetterO();
        classy.displayLetterN();
        classy.displayLetterA();
        classy.displayLetterT();
        classy.displayLetterH();
        classy.displayLetterA();
        classy.displayLetterN();

    }//end of main

    public void displayLetterJ()
    {
        System.out.println("  " + c + c + c);
        System.out.println("    " + c);
        System.out.println("    " + c);
        System.out.println(c + "   " + c);
        System.out.println(c + c + c + c + c);

    }

    public void displayLetterA()
    {
        System.out.println();
        System.out.println("   " + c);
        System.out.println("  " + c + " " + c);
        System.out.println(" " + c + " " + c + " " + c);
        System.out.println(c + "     " + c);
        System.out.println(c + "     " + c);

    }

    public void displayLetterO()
    {
        System.out.println();
        System.out.println("  " + c + c);
        System.out.println(" " + c + "  " + c);
        System.out.println(c + "    " + c);
        System.out.println(c + "   " + c);
        System.out.println("  " + c + c);

    }

    public void displayLetterN()
    {
        System.out.println();
        System.out.println(c + "    " + c);
        System.out.println(c + " " + c + "  " + c);
        System.out.println(c + "  " + c + " " + c);
        System.out.println(c + "   " + c + c);
        System.out.println(c + "    " + c);

    }

    public void displayLetterH()
    {//H accessor
        System.out.println();
        System.out.println(c + "   " + c);
        System.out.println(c + "   " + c);
        System.out.println(c + c + c + c + c);
        System.out.println(c + "   " + c);
        System.out.println(c + "   " + c);

    }

    public void displayLetterT()
    {
        System.out.println();
        System.out.println(c + c + c + c + c);
        System.out.println("  " + c);
        System.out.println("  " + c);
        System.out.println("  " + c);
        System.out.println("  " + c);

    }
}

Answer 1

主要问题是，如果变量不是static，那么它附加到类的实例，因此您无法从static上下文中引用它。这是因为非静态变量表示特定实例的某种状态。

您的main()是静态的，因此c = ..是非法的。尝试使用classy.c = ..，这样您就会引用您在静态方法中创建的String实例的特定Lab3。

Answer 2

有几个方面可以解决这个问题，一个可能是： 在主mehod中定义c String，然后将c String作为参数传递给所有方法。

其他方法可以将c String定义为类属性（非静态），然后在方法中使用“this.c”来引用c String。

1-如果将属性声明为静态，则表示该属性将与该类的所有实例共用。 非静态属性仅是当前类实例的一部分。

Answer 3

仅在方法main

中初始化String

String c = input.next（）;

Answer 4

你应该重构你的方法以这种方式使用字符c

public void displayLetterJ(String c)
{
   System.out.println("  "+c+c+c);
   System.out.println("    " +c);
   System.out.println("    " +c);
   System.out.println(c + "   " + c);
   System.out.println(c+ c+ c + c +c);
}

并从main调用

classy.displayLetterJ("*");

Answer 5

我认为您应该使用私有实例字段c和公共getter和setter：

public class Lab3 {

   private String c;

   public void setC(String c) 
   {
        this.c = c;
   }

   public String getC() 
   {
        return this.c;
   }

....


}

然后你可以用你的主要方法说：

Lab3 classy  = new Lab3();
Scanner input=new Scanner(System.in);

System.out.print("Which character would you like to display?");

classy.setC(input.next());

Answer 6

我不知道这个目的是什么......但这应该没有静态

import java.util.Scanner;


/**
 *
 * @author john
 */
 public class Lab3 {


 public static void main(String[] args) {
     String c;
     Lab3 classy  = new Lab3();
     Scanner input=new Scanner(System.in);

          System.out.print("Which character would you like to display?");

          c = input.next();

        System.out.println("My name is Jonathan");
        classy.displayLetterJ(c);
        classy.displayLetterO(c);
        classy.displayLetterN(c);
        classy.displayLetterA(c);
        classy.displayLetterT(c);
        classy.displayLetterH(c);
        classy.displayLetterA(c);
        classy.displayLetterN(c);

      }//end of main
public void displayLetterJ(String c) {
    System.out.println("  "+c+c+c);
    System.out.println("    " +c);
    System.out.println("    " +c);
    System.out.println(c + "   " + c);
    System.out.println(c+ c+ c + c +c);

 }
 public void displayLetterA(String c){
    System.out.println();
    System.out.println("   "+c);
    System.out.println("  "+c+" "+c);
    System.out.println(" "+c+" "+c+" "+c);
    System.out.println(c+"     "+c);
    System.out.println(c+"     "+c);

}
  public void displayLetterO(String c){
    System.out.println();
    System.out.println("  "+c+c);
    System.out.println(" "+c+"  "+c);
    System.out.println(c+"    "+c);
    System.out.println(c+"   "+c);
    System.out.println("  "+c+c);

}
  public void displayLetterN(String c){
    System.out.println();
    System.out.println(c+"    "+c);
    System.out.println(c+" "+c+"  "+c);
    System.out.println(c+"  "+c+" "+c);
    System.out.println(c+"   "+c+c);
    System.out.println(c+"    "+c);

}
 public void displayLetterH(String c){//H accessor
    System.out.println();
    System.out.println(c+"   "+c);
    System.out.println(c+"   "+c);
    System.out.println(c+c+c+c+c);
    System.out.println(c+"   "+c);
    System.out.println(c+"   "+c);

}
  public void displayLetterT(String c){
    System.out.println();
    System.out.println(c+c+c+c+c);
    System.out.println("  "+c);
    System.out.println("  "+c);
    System.out.println("  "+c);
    System.out.println("  "+c);

    }

}

Answer 7

更改

public class Lab3 {
 static String c;

in

public class Lab3 {
     private String c;   
     public void setC(String c){this.c=c;}

变化：

public static void main（String [] args）{

 Lab3 classy  = new Lab3();
 Scanner input=new Scanner(System.in);
 c = input.next();
 classy.setC(c);

 .....
}