获取其他类中的变量

Question

我需要inString在其他班上变数。我怎样才能做到这一点？

public class main {
    public static StringBuffer inString;


    public static void main(String[] args) {
        inString = new StringBuffer("Our aim is to make a 15 realistic game, where grinding powerlines and doing a tailwhip isn't easy, like in the real world. A game in which you will feel like you're actual riding. A game in which creativity and beauty are combined. ");
        inString = new StringBuffer(inString.toString().replaceAll(" +", " "));
        }
}

所以我尝试System.out.println(main.inString);在Textcl.class中使用，但是得到了null。

Answer 1

您将得到空值，因为inString从未按Robert Kilar在注释中正确指出的那样进行初始化。

您可以通过使用类名来引用静态变量。

示例ClassName.variablename。就你而言

    main.inString

运行您的主类。当您运行inString时，将在该类的构造函数中对其进行初始化。现在，您可以在Myclass中引用相同的内容，如下所示。

public class main {
public static StringBuffer inString;

public main()
{
inString = new StringBuffer("Our aim is to make a 15 realistic game, where grinding powerlines and doing a tailwhip isn't easy, like in the real world. A game in which you will feel like you're actual riding. A game in which creativity and beauty are combined. ");
inString = new StringBuffer(inString.toString().replaceAll(" +", " "));
new MyClass();
}
public static void main(String[] args) {
    new main();
    }
}

现在在MyClass中引用静态变量。

class MyClass {

public MyClass() {
    System.out.println("............."+main.inString);// refer to static variable
}
}

您还可以将变量传递给类的构造函数。

public class main {
public  StringBuffer inString;

 public main()
  {
    inString = new StringBuffer("Our aim is to make a 15 realistic game, where grinding powerlines and doing a tailwhip isn't easy, like in the real world. A game in which you will feel like you're actual riding. A game in which creativity and beauty are combined. ");
    inString = new StringBuffer(inString.toString().replaceAll(" +", " "));  
    new MyClass(inString);
 }
public static void main(String[] args) {
    new main();

    }
}

然后在Myclass

 public class MyClass
 {
        public MyClass(StringBuffer value)
        {
          System.out.println("............."+value);
        }
 }