Stack Memory and Heap Space in Java

memory.java

/* https://www.baeldung.com/java-stack-heap */
class Person {
    int pid;
    String name;
    // constructor, setter/getters
}

public class Driver {
    /**
      * 1. Upon entering the main() method, a space in stack memory would be created to store primitives
      *    and references of this method. i) the primitive value of integer id. ii) the reference variable
      *    p of type Person will also be created in stack memory which will point to the actual object
      *    in th heap
      *
      * 2. The call to the parameterized constructor Person(int, String) from main() will allocate further
      *    memory on top of the previous stack: i) the this object reference of the calling object in the
      *    stack memory. ii) the primitive value id in the stack memory. iii) The reference variable of String
      *    argument personName which will point to the actual string from string pool in heap memory
      *
      * 3. This default constructor is further calling setPersonalName() method, for which further allocation
      *    will take place in stack memory on top of previous one. Again, store local variables.
      *
      * 4. However, for the newly created object p of type Person, all instance variables will stored in heap memory
      *
      */
    public static void main(String[] args) {
        int id = 23;
        String pName = "Jon"; // pName reference in Stack, but the String Pool in Heap
        Person p = null;
        p = new Person(id, pName);
    }
}