Confusing Recursive StackOverflowError program

Question

I wrote down a recursive program in Java (for fun) where a few things are not clear :

public class methodTest
{
    public static double methodTest()
    {
        System.out.println("qwerty") ; // sign that this method is called
        methodTest obj1 = new methodTest() ; // creating an object (perhaps unnessary)
        System.out.println(methodTest.methodTest()) ; // ??!
        return methodTest() ; // returning the same function
    }
}

1. Why, if the return datatype is double, my BlueJ compiler not showing a syntax error when returning a method ?
2. How can this program be stopped if the number of times this method is 'recursed' with and without using an incrementing variable ? [I tried using a static int initialised in the class (before methodTest()) and incrementing it in the method but it shows "unreachable statement"]
3. What is the computer doing when it tries to execute the System.out.println(methodTest.methodTest()) statement ?
4. Why does the compiler give a syntax error (cannot find symbol - variable obj1) when I replace (in System.out.println(methodTest.methodTest())) .methodTest with .obj1 ?
   
   Please answer my questions ☝️

Answer 1

Here is one way to approach this.

Notes:

• The class exposes a simple method that kicks off the recursion.
• The recursive method checks for the number of recursions.
• It returns a hardcoded value because I have no idea what you're actually trying to do.

public class MySampleClass
{
    private static double methodTestPrivate(int callIndex)
    {
       //Check for terminating condition
       if (callIndex >= 10)
           return 42.0;

       //Recursive call
       return methodTestPrivate(callIndex+1);
    }

    public static double methodTest()
    {  
        return methodTestPrivate(0);
    }
}

public class MyProgram
{
    public static void main(String[] args)
    {
        System.out.print(MySampleClass.methodTest());
    }
}