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Java: how to have global values inside a class?

I want less methods. I want a common global TestClass from which I could use any of its value inside the class.

import java.util.*;
import java.io.*;

public class TestClass {
        TestClass(String hello){
                String hallo = hello;
                String halloSecond = "Saluto!";
        }
        public static void main(String[] args) {
                TestClass test = new TestClass("Tjena!");
                System.out.println("I want "Tjena!": " + test.hallo);
                TestClass testSecond = new TestClass("1");
                System.out.println("I want Saluto!:" + test.halloSecond);
                System.out.println("I want Saluto!:" + testSecond.halloSecond);

                // How can I get glob.vars like the "Saluto!"?
        }
}

[Clarification Needed] I cannot understand the no-use of GLOB.VARS. Please, see the code belowe where you cannot access the GLOB.VARS without an instance, hence the error. If I quarantee no malicious code can make an instance, is there any problem in using GLOB.vars?

$ javac TestClass.java 
TestClass.java:19: non-static variable hallo cannot be referenced from a static context
  System.out.println("It did not get to the GLOB.VAR: " + hallo);
                                             ^
1 error
$ cat TestClass.java 
import java.util.*;
import java.io.*;

public class TestClass {
        public String hallo;
        public String halloSecond;

        TestClass(String hello){
                hallo = hello;
                halloSecond = "Saluto!";
        }
        public static void main(String[] args) {
                TestClass test = new TestClass("Tjena!");
      System.out.println("It did not get to the GLOB.VAR" + hallo);
        }
}
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1 Answer

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by (71.8m points)

I want less methods.

You shouldn't. Methods should not be measured by count or size. They should exist if they have a separate responsibility.

I want a common global TestClass from which I could use any of its value inside the class.

This doesn't make much sense. I guess you need instance variables

 private String hello;
 private String helloSecond;

 TestClass(String hello){
        hallo = hello;
        halloSecond = "Saluto!";
 }

 public String getHello() { return hello; }
 public String getHelloSecond() { return helloSecond; }

How to have global values inside a class?

global variables can be achieved by defining them static:

public static String var;

But using these is a very bad practice. You must not use them.


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