How to pass string between two activities

I have two activities A and B, and from activity A, I click on a button that opens a dialog box which contains a form consisting of two edit text fields and a button(the button in the dialog box is used to start activity B). So, my question is: how do I pass a string from activity B to activity A, but without closing the dialog box(the string will be used to fill one of the two edit text fields).

You need to create a class to store the variable. In ActivityB use set the value of the variable, the created class stores it and in ActivityA get the value of the variable.

1. Create a class: GlobalVars.java. In this class put this:

   public class GlobalVars extends Application {

   private static String var2;
   
   public static String getVar() {
       return var2;
   }
   
   public static void setVar(String var) {
   var2 = var;
   }
   

   }

In ActivityB put this line in to the appropriate place:

String something;
GlobalVars.setVar(something);

In ActivityA put this line in to the appropriate place:

String getsomething = GlobalVars.getVar();

And that's it!