feat: Add ArrayListDemo7 to explore constructors

and methods via reflection

This demo showcases how to use Java
Reflection API to inspect the
internal structure of the ArrayList class.

Key highlights:
• Obtains the Class object for java.util.ArrayList using ArrayList.class.
• Retrieves all declared constructors with getDeclaredConstructors().
• Retrieves all declared methods with getDeclaredMethods().
• Iterates over constructors and methods, printing their names.

Why this is useful:
• Demonstrates reflection capabilities for runtime class inspection.
• Helps understand how many constructors and methods exist inside
  core library classes like ArrayList.
• Useful for debugging, framework design,
and meta-programming tasks
where behavior adapts based on runtime
class analysis.

Output:
- Prints the list of all constructor
signatures of ArrayList.
- Prints the names of all methods (public,
protected, private, and package-private declared within ArrayList).

Signed-off-by: https://github.com/Someshdiwan <someshdiwan369@gmail.com>

Author: Someshdiwan

Section 25 Collections Frameworks/List Interface/ArrayList/src/ArrayListDemo7.java

@@ -0,0 +1,26 @@
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+
+public class ArrayListDemo7 {
+    public static void main(String[] args) {
+        // Get the Class object of ArrayList
+        Class<?> classOB = ArrayList.class;
+
+        // Get all constructors of ArrayList
+        Constructor<?> [] declaredConstructors = classOB.getDeclaredConstructors();
+
+        // Get all methods of ArrayList
+        Method[] declaredMethods = classOB.getDeclaredMethods();
+
+        // Print all constructor names
+        for(Constructor<?> constructor : declaredConstructors) {
+            System.out.println(constructor.getName());
+        }
+
+        // Print all method names
+        for(Method method : declaredMethods) {
+            System.out.println(method.getName());
+        }
+    }
+}