understand 3 types of constructors

Author: georgecatalin

Learn_CPP_Programming_Deep_Dive/Section 11 OOP/Constructors/main.cpp

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+#include <iostream>
+
+using namespace std;
+
+class Rectangle
+{
+    private:
+        int length;
+        int breadth;
+
+    public:
+        /* Accessors go here */
+        int getLength()
+        {
+            return length;
+        }
+        int getBreadth()
+        {
+            return breadth;
+        }
+
+        /* Mutators go here */
+        void setLength(int l)
+        {
+            if(l<0)
+            {
+                length = 0;
+            }
+            else
+            {
+                length = l;
+            }
+        }
+        void setBreadth(int b)
+        {
+            if(b<0)
+            {
+                breadth = 0;
+            }
+            else
+            {
+                breadth = b;
+            }
+        }
+
+        /* There are 4 types of constructors:  1. Compiler provided 2. no-parameterized 3. parameterized  4. copy constructor */
+        Rectangle()
+        {
+            /* this is non parameterized constructor */
+            length = 0;
+            breadth = 0;
+        }
+
+        Rectangle(int l, int b)
+        {
+            /* this is a parameterized constructor */
+            setLength(l);
+            setBreadth(b);
+        }
+
+        Rectangle(Rectangle &r)
+        {
+            /* this is a copy constructor - i am providing a copy example */
+            length = r.length;
+            breadth = r.breadth;
+        }
+
+        int area()
+        {
+            return length * breadth;
+        }
+
+};
+
+int main(void)
+{
+    Rectangle r1;
+    Rectangle r2(10,20);
+
+    Rectangle r3(r2);
+
+    cout<<"Area of non-parameterized rectangle is "<<r1.area()<<endl;
+    cout<<"Area of non-parameterized rectangle is "<<r2.area()<<endl;
+    cout<<"Area of non-parameterized rectangle is "<<r3.area()<<endl;
+
+    return 0;
+
+}