feat: Explain this vs super in Java with family business analogy and code demos

WHAT the explanation does:
- Uses a **real-world analogy** of a father (Parent class) and son (Child class) managing a family business.
- Maps `this` to the son's resources and responsibilities, and `super` to the father's assets and methods.
- Provides clear Java code examples:
  - `this` for distinguishing between instance and local variables.
  - `super` for accessing parent class fields and methods when overridden in the child.
- Shows runtime polymorphism: child methods override parent ones, but `super` can still invoke the parent’s logic.

WHY this matters:
- `this` and `super` are cornerstones of object-oriented programming in Java.
- They resolve ambiguity when variable or method names overlap across local, instance, and parent scopes.
- Understanding their use is critical for constructor chaining, method overriding, and clear hierarchical design.
- The family business analogy grounds these abstract concepts in an everyday scenario.

HOW it works:
1. **`this` keyword**:
   - Refers to the current object.
   - Used to access current class fields/methods and differentiate local variables from instance variables.
   - Enables constructor chaining with `this()`.
   - In analogy: the son pointing to “my store” or “my way of serving customers”.
2. **`super` keyword**:
   - Refers to the parent object.
   - Used to access parent class fields/methods hidden or overridden by the child.
   - Ensures parent constructors execute with `super()`.
   - In analogy: the son acknowledging “Dad’s store” or “Dad’s method of serving customers”.
3. Code demo (Son vs Father classes) shows how `this.store` vs `super.store` and `this.serveCustomers()` vs `super.serveCustomers()` resolve to different outputs.

Tips and gotchas:
- Both `this()` and `super()` must be the **first statement** in a constructor.
- If not explicitly written, `super()` is added automatically by the compiler to call the no-arg parent constructor.
- `this` and `super` cannot be used in static contexts.
- `super` cannot access private members of the parent class.
- Overusing constructor chaining can reduce readability; use judiciously.

Use-cases / analogies:
- **Family business**: Son runs his own shop but still refers back to Dad’s shop when needed.
- **House analogy**: Inside your room → `this.room`; referring to parent’s room → `super.room`.
- **Real software**:
  - `this`: useful when parameter names shadow fields (`this.x = x`).
  - `super`: essential in frameworks where overridden methods still rely on parent logic (e.g., overriding paintComponent in Swing but calling `super.paintComponent()` first).

Short key: java-oop this-vs-super constructor-chaining method-overriding inheritance analogy.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Section15InnerClasses/src/Real-World Analogy for `this` vs `super`.md

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+# Real-World Analogy for `this` vs `super`:
+
+Imagine a family business** where a father (Parent class) owns a store, 
+and his son (Child class) is managing it. 
+
+The father has some assets and methods of running the business, and the son inherits those but can also introduce his own ways.
+
+---
+
+## 1️⃣ `this` → Refers to the Son (Current Class):
+
+* The son wants to refer to his own set of responsibilities and resources.
+* If he wants to access his own account, he says "my bank account" (`this.account`).
+* If he introduces a new way of handling customers, he uses his own method (`this.serveCustomers()`).
+
+💻 Code Representation
+
+```java
+class Son {
+    String name;
+
+    Son(String name) {
+        this.name = name;  // 'this' differentiates between instance and parameter
+    }
+
+    void introduce() {
+        System.out.println("I am " + this.name + ", managing the store.");
+    }
+}
+```
+
+✅ `this.name = name;` avoids confusion between the local variable and the instance variable.
+---
+
+2️⃣ `super` → Refers to the Father (Parent Class)
+
+* The son wants to access things that belong to his father.
+* If he needs money from his father's account, he says "Dad’s bank account" (`super.account`).
+* If he wants to follow the traditional way of handling customers, he calls Dad’s method** (`super.serveCustomers()`).
+
+```java
+class Father {
+    String store = "Dad's Grocery Store";
+
+    void serveCustomers() {
+        System.out.println("Serving customers the traditional way.");
+    }
+}
+
+class Son extends Father {
+    String store = "Modern Supermarket";
+
+    void serveCustomers() {
+        System.out.println("Serving customers with modern technology.");
+    }
+
+    void showStore() {
+        System.out.println("My store: " + this.store);   // Son's store
+        System.out.println("Dad's store: " + super.store);  // Father's store
+    }
+
+    void serveCustomersBothWays() {
+        this.serveCustomers();   // Calls Son's method
+        super.serveCustomers();  // Calls Father's method
+    }
+}
+```
+
+💡 Key Observations
+
+* `this.store` → Refers to the son's store.
+* `super.store` → Refers to the father's store.
+* `this.serveCustomers()` → Calls the son's new way of handling customers.
+* `super.serveCustomers()` → Calls the father's traditional method.
+
+---
+
+🛒 Real-Life Scenario Output
+
+```java
+public class FamilyBusiness {
+    public static void main(String[] args) {
+        Son son = new Son();
+        son.showStore();
+        son.serveCustomersBothWays();
+    }
+}
+```
+
+### 📌 Output
+
+```
+My store: Modern Supermarket
+Dad's store: Dad's Grocery Store
+Serving customers with modern technology.
+Serving customers the traditional way.
+```
+
+---
+
+## 📌 Summary in Simple Words
+
+|   Concept   |   Analogy                                            | Java Usage                                                              |
+| ----------- | ---------------------------------------------------- | ----------------------------------------------------------------------- |
+| `this`      | Son referring to his own store, name, or method      | Refers to the current class (instance variables, methods, constructors) |
+| `super`     | Son referring to his father's store, name, or method | Refers to the parent class (variables, methods, constructors)           |
+
+---
+
+## Final Thought 💭
+
+If you’re **inside your own house**, you say **“this is my room”** (`this.room`).
+If you refer to your **parent’s house**, you say **"super house"** (`super.house`).
+
+This analogy helps in understanding how `this` and `super` work in Java!
+
+---