diff --git a/Constructor/Untitled1.cpp b/Constructor/Untitled1.cpp
new file mode 100644
index 0000000..deceb5d
--- /dev/null
+++ b/Constructor/Untitled1.cpp
@@ -0,0 +1,35 @@
+#include<iostream>
+using namespace std;
+class area_circle{
+		int r,area;
+	public:
+		void read_data(){
+			cin>>r;
+		}
+		
+		void publish_data()
+		{
+			cout<<area;
+		}
+};
+
+
+class volume:public area_circle
+{
+	int x;
+	public:
+		void get_data(){
+		}
+		void show_data(){
+			
+		}
+};
+
+int main(){
+	volume B;
+	B.get_data();
+	B.show_data();
+	B.read_data();
+	B.publish_data();
+	return 0;
+}
diff --git a/Constructor/Untitled1.exe b/Constructor/Untitled1.exe
new file mode 100644
index 0000000..956f2bf
Binary files /dev/null and b/Constructor/Untitled1.exe differ
diff --git a/Constructor/constructor-1.cpp b/Constructor/constructor-1.cpp
new file mode 100644
index 0000000..1e625a8
--- /dev/null
+++ b/Constructor/constructor-1.cpp
@@ -0,0 +1,30 @@
+#include<iostream>
+#include<string.h>
+using namespace std;
+class student{
+	private:
+		int roll;
+		char name[30];
+		
+	public:
+		student(int x, char y[])    // parameterized constructor function
+		{
+		  roll= x;
+		  strcpy(name,y)	;
+		}
+		void show_data(){
+		    cout<<"\n Roll no :"<<roll;
+    		cout<<"\n Name    :"<<name;
+		}
+};
+
+int main(){
+	//student s;     // constructor function runs at the time of object creation
+	
+	student s(10,"Manan");   // implicit call
+	
+	student s1 = student(20,"Ramji");   // explicit call
+	s.show_data();
+	s1.show_data();
+	return 0;
+}
diff --git a/Constructor/constructor-1.exe b/Constructor/constructor-1.exe
new file mode 100644
index 0000000..a9a6447
Binary files /dev/null and b/Constructor/constructor-1.exe differ
diff --git a/Constructor/contructir-with-default-values.cpp b/Constructor/contructir-with-default-values.cpp
new file mode 100644
index 0000000..36999c6
--- /dev/null
+++ b/Constructor/contructir-with-default-values.cpp
@@ -0,0 +1,27 @@
+#include<iostream>
+#include<string.h>
+using namespace std;
+class student{
+	private:
+		int roll;
+		char name[30];
+		
+	public:
+		student(int x=10, char y[]="Sumit Singh")    // parameterized constructor with default values
+		{
+		  roll= x;
+		  strcpy(name,y)	;
+		}
+		void show_data(){
+		    cout<<"\n Roll no :"<<roll;
+    		cout<<"\n Name    :"<<name;
+		}
+};
+
+int main(){
+	
+	//student s;     // constructor function runs at the time of object creation
+	student s(30,"Hitesg");
+	s.show_data();
+	return 0;
+}
diff --git a/Constructor/contructir-with-default-values.exe b/Constructor/contructir-with-default-values.exe
new file mode 100644
index 0000000..c4ad8c6
Binary files /dev/null and b/Constructor/contructir-with-default-values.exe differ
diff --git a/Constructor/destructir-1.cpp b/Constructor/destructir-1.cpp
new file mode 100644
index 0000000..e7005ab
--- /dev/null
+++ b/Constructor/destructir-1.cpp
@@ -0,0 +1,22 @@
+#include<iostream>
+#include<string.h>
+using namespace std;
+class student{
+	public:
+	student(){
+		cout<<"\n I am constructor"		;
+		}
+	~student(){
+		cout<<"\n Inside destrctor";
+	}
+};
+
+int main(){
+	
+	student s;
+	 {
+	 	student s1;
+	 }
+	 student s2;
+	return 0;
+}
diff --git a/Constructor/destructir-1.exe b/Constructor/destructir-1.exe
new file mode 100644
index 0000000..57205b0
Binary files /dev/null and b/Constructor/destructir-1.exe differ
diff --git a/Constructor/overloading.cpp b/Constructor/overloading.cpp
new file mode 100644
index 0000000..e0e4211
--- /dev/null
+++ b/Constructor/overloading.cpp
@@ -0,0 +1,34 @@
+#include<iostream>
+#include<string.h>
+using namespace std;
+class student{
+	private:
+		int roll;
+		char name[30];
+		
+	public:
+		
+		student(){
+			roll=20;
+			strcpy(name,"Rakesh");
+		}
+		
+		student(int x, char y[])    // parameterized constructor with default values
+		{
+		  roll= x;
+		  strcpy(name,y)	;
+		}
+		
+		void show_data(){
+		    cout<<"\n Roll no :"<<roll;
+    		cout<<"\n Name    :"<<name;
+		}
+};
+
+int main(){
+	
+	//student s;     // constructor function runs at the time of object creation
+	student s(40,"rajesh mandal");
+	s.show_data();
+	return 0;
+}
diff --git a/Constructor/overloading.exe b/Constructor/overloading.exe
new file mode 100644
index 0000000..f3617f8
Binary files /dev/null and b/Constructor/overloading.exe differ
diff --git a/File_handling/demo.txt b/File_handling/demo.txt
new file mode 100644
index 0000000..bcfd544
--- /dev/null
+++ b/File_handling/demo.txt
@@ -0,0 +1,3 @@
+How to learn and then earn using C++
+This is my second line of text
+ This is third line having 	 tab and another spacing chars
\ No newline at end of file
diff --git a/File_handling/file_handling-1.cpp b/File_handling/file_handling-1.cpp
new file mode 100644
index 0000000..b9120f0
--- /dev/null
+++ b/File_handling/file_handling-1.cpp
@@ -0,0 +1,12 @@
+#include<fstream>
+#include<iostream>
+using namespace std;
+int main(){
+	ofstream handa;
+	handa.open("demo.txt");
+	handa<<"How to learn and then earn using C++";
+	handa<<"\nThis is my second line of text";
+	handa<<"\n This is third line having \t tab and another spacing chars";
+	handa.close();
+	return 0;
+}
diff --git a/File_handling/file_read_1.cpp b/File_handling/file_read_1.cpp
new file mode 100644
index 0000000..be34259
--- /dev/null
+++ b/File_handling/file_read_1.cpp
@@ -0,0 +1,12 @@
+#include<fstream>
+#include<iostream>
+using namespace std;
+int main(){
+	ifstream object;
+	char name[300];
+	object.open("demo.txt");
+	object>>name;   // read one word at a time
+	cout<<"\n Entered Name :"<<name;
+	object.close();
+	return 0;
+}
diff --git a/File_handling/file_read_2.cpp b/File_handling/file_read_2.cpp
new file mode 100644
index 0000000..53b5f6c
--- /dev/null
+++ b/File_handling/file_read_2.cpp
@@ -0,0 +1,12 @@
+#include<fstream>
+#include<iostream>
+using namespace std;
+int main(){
+	ifstream object;
+	char name[300];
+	object.open("demo.txt");
+	object.getline(name,300);
+	cout<<"\n Entered Value :"<<name;
+	object.close();
+	return 0;
+}
diff --git a/File_handling/file_read_3.cpp b/File_handling/file_read_3.cpp
new file mode 100644
index 0000000..bea9eb9
--- /dev/null
+++ b/File_handling/file_read_3.cpp
@@ -0,0 +1,18 @@
+#include<fstream>
+#include<iostream>
+using namespace std;
+int main(){
+	ifstream object;
+	char name[300];
+	object.open("demo.txt");
+	
+	object.getline(name,300);
+	cout<<"\n Entered Value :"<<name;
+	object.getline(name,300);
+	cout<<"\n Entered Value :"<<name;
+	object.getline(name,300);
+	cout<<"\n Entered Value :"<<name;
+	
+	object.close();
+	return 0;
+}
diff --git a/File_handling/file_read_char_eof.cpp b/File_handling/file_read_char_eof.cpp
new file mode 100644
index 0000000..876836c
--- /dev/null
+++ b/File_handling/file_read_char_eof.cpp
@@ -0,0 +1,20 @@
+// file read char wise + EOF function
+
+
+#include<fstream>
+#include<iostream>
+using namespace std;
+int main(){
+	ifstream object;
+	char ch;
+	object.open("file_read_eof.cpp");
+	
+	while(!object.eof())
+	   {
+	   	 object.get(ch);
+	   	 cout<<ch;
+	   }
+	
+	object.close();
+	return 0;
+}
diff --git a/File_handling/file_read_eof.cpp b/File_handling/file_read_eof.cpp
new file mode 100644
index 0000000..8c58550
--- /dev/null
+++ b/File_handling/file_read_eof.cpp
@@ -0,0 +1,20 @@
+// file read and using EOF function
+
+
+#include<fstream>
+#include<iostream>
+using namespace std;
+int main(){
+	ifstream object;
+	char name[300];
+	object.open("demo.txt");
+	
+	while(!object.eof())
+	   {
+	   	 object.getline(name,300);
+	   	 cout<<name;
+	   }
+	
+	object.close();
+	return 0;
+}
diff --git a/File_handling/file_read_eof_simulta.cpp b/File_handling/file_read_eof_simulta.cpp
new file mode 100644
index 0000000..5951c98
--- /dev/null
+++ b/File_handling/file_read_eof_simulta.cpp
@@ -0,0 +1,18 @@
+// file read char wise + EOF function
+
+
+#include<fstream>
+#include<iostream>
+using namespace std;
+int main(){
+	ifstream object;
+	char ch;
+	object.open("file_read_eof.cpp");
+	
+	while( object.get(ch))  // checking end of file using file object
+	    cout<<ch;
+	   
+	
+	object.close();
+	return 0;
+}
diff --git a/File_handling/file_read_eof_using_object.cpp b/File_handling/file_read_eof_using_object.cpp
new file mode 100644
index 0000000..68e2de3
--- /dev/null
+++ b/File_handling/file_read_eof_using_object.cpp
@@ -0,0 +1,20 @@
+// file read char wise + EOF function
+
+
+#include<fstream>
+#include<iostream>
+using namespace std;
+int main(){
+	ifstream object;
+	char ch;
+	object.open("file_read_eof.cpp");
+	
+	while(object)  // checking end of file using file object
+	   {
+	   	 object.get(ch);
+	   	 cout<<ch;
+	   }
+	
+	object.close();
+	return 0;
+}
diff --git a/File_handling/total_words.cpp b/File_handling/total_words.cpp
new file mode 100644
index 0000000..44bb8ad
--- /dev/null
+++ b/File_handling/total_words.cpp
@@ -0,0 +1,17 @@
+// program to find out total no of words in a text file
+#include<fstream>
+#include<iostream>
+using namespace std;
+int main(){
+	ifstream fin;
+	fin.open("demo.txt");
+	char word[100];
+	int count=0;
+	while(fin){
+		fin>>word;
+		count++;
+	}
+	fin.close();
+	cout<<"\nTotal words :"<<count;
+	return 0;
+}
diff --git a/classes/initialize_class_variable_wrong.cpp b/classes/initialize_class_variable_wrong.cpp
index d0a5d0b..f934f96 100644
--- a/classes/initialize_class_variable_wrong.cpp
+++ b/classes/initialize_class_variable_wrong.cpp
@@ -7,6 +7,11 @@ class student{
 		char name[30];
 		
 	public:
+		student()    // constructor function
+		{
+		  roll= 10;
+		  strcpy(name,"manan")	;
+		}
 		void show_data(){
 		    cout<<"\n Roll no :"<<roll;
     		cout<<"\n Name    :"<<name;
@@ -15,7 +20,7 @@ class student{
 
 
 int main(){
-	student s;
+	student s;     // constructor function runs at the time of object creation
 	s.show_data();
 	return 0;
 }
diff --git a/inheritance/Untitled1.cpp b/inheritance/Untitled1.cpp
new file mode 100644
index 0000000..d100ab5
--- /dev/null
+++ b/inheritance/Untitled1.cpp
@@ -0,0 +1,35 @@
+#include<iostream>
+using namespace std;
+class area_circle{
+		int r,area;
+	public:
+		void read_data(){
+			cin>>r;
+		}
+		
+		void publish_data()
+		{
+			cout<<area;
+		}
+};
+
+
+class volume:public area_circle   // using public 
+{
+	int x;
+	public:
+		void get_data(){
+		}
+		void show_data(){
+			
+		}
+};
+
+int main(){
+	volume B;
+	B.get_data();
+	B.show_data();
+	B.read_data();
+	B.publish_data();
+	return 0;
+}
diff --git a/inheritance/Untitled4.cpp b/inheritance/Untitled4.cpp
new file mode 100644
index 0000000..19d5d7f
--- /dev/null
+++ b/inheritance/Untitled4.cpp
@@ -0,0 +1,19 @@
+#include<iostream>
+using namespace std;
+class mukul
+{
+	private:
+		int a;
+	public:
+		int b;
+	protected:
+		int c;
+};
+
+int main(){
+	mukul obj;
+	obj.a=10;
+	obj.b=20;
+	obj.c=30;
+	return 0;
+}
diff --git a/inheritance/private_inheritance.cpp b/inheritance/private_inheritance.cpp
new file mode 100644
index 0000000..ce19d3a
--- /dev/null
+++ b/inheritance/private_inheritance.cpp
@@ -0,0 +1,24 @@
+#include<iostream>
+using namespace std;
+class area_circle{
+		int r,area;
+	public:
+		void read_data(){}
+		void publish_data(){}
+};
+class volume:private area_circle   // using private
+{
+	int x;
+	public:
+		void get_data(){}
+		void show_data(){}
+};
+
+int main(){
+	volume B;
+	B.get_data();
+	B.show_data();
+	B.read_data();
+	B.publish_data();
+	return 0;
+}
diff --git a/inheritance/private_members.cpp b/inheritance/private_members.cpp
new file mode 100644
index 0000000..7748f28
--- /dev/null
+++ b/inheritance/private_members.cpp
@@ -0,0 +1,30 @@
+#include<iostream>
+using namespace std;
+class area_circle{
+		int r,area;
+		void calculate();
+	public:
+		void read_data(){
+		   cin>>r;
+		}
+		void publish_data(){}
+};
+class volume:public area_circle   // using private
+{
+	int x;
+	public:
+		void get_data(){
+		  cin>>r;
+		}
+		void show_data(){}
+};
+
+int main(){
+	area_circle A;
+	A.read_data();
+	
+	volume B;
+	B.calculate();
+	B.get_data();
+	return 0;
+}
diff --git a/inheritance/protect_member_inheritance.cpp b/inheritance/protect_member_inheritance.cpp
new file mode 100644
index 0000000..a0e3406
--- /dev/null
+++ b/inheritance/protect_member_inheritance.cpp
@@ -0,0 +1,32 @@
+#include<iostream>
+using namespace std;
+class area_circle{
+	protected:
+		int r,area;
+		void calculate();
+	public:
+		void read_data(){
+		   cin>>r;
+		}
+		void publish_data(){}
+};
+
+class volume:public area_circle   // using private
+{
+	int x;
+	
+	public:
+		void get_data(){
+		  cin>>r;
+		}
+		void show_data(){}
+};
+
+int main(){
+	area_circle A;
+	A.read_data();
+	
+	volume B;
+	B.get_data();
+	return 0;
+}
diff --git a/inheritance/protect_member_inheritance.exe b/inheritance/protect_member_inheritance.exe
new file mode 100644
index 0000000..fe7e26d
Binary files /dev/null and b/inheritance/protect_member_inheritance.exe differ
diff --git a/inheritance/protected_member_classs.cpp b/inheritance/protected_member_classs.cpp
new file mode 100644
index 0000000..19d5d7f
--- /dev/null
+++ b/inheritance/protected_member_classs.cpp
@@ -0,0 +1,19 @@
+#include<iostream>
+using namespace std;
+class mukul
+{
+	private:
+		int a;
+	public:
+		int b;
+	protected:
+		int c;
+};
+
+int main(){
+	mukul obj;
+	obj.a=10;
+	obj.b=20;
+	obj.c=30;
+	return 0;
+}