Time Class Program in C++ using operator overloading to add two different Time values

The following program is an implementation of operator overloading in C++ to add two time values in the format HH:MM:SS to the resulting time along with rounding off when 24 hours is reached.
A Time class is created and Operator + is overloaded to add the two Time Class Objects.


The complete source code in C++ to Implement Time class is given below

 #include<iostream.h>  


 #include<conio.h>  
 class time  
 {  
 public:  
 time()  
 {  
 hr=0;  
 min=0;  
 sec=0;  
 }  
 int hr,min,sec;  
 void read()  
 {  
 cout<<"Hours=";  
 cin>>hr;  
 cout<<"\nMinutes=";  
 cin>>min;  
 cout<<"\nSeconds=";  
 cin>>sec;  
 }  
 time operator +(time t2)  
 {  
 time t3;  
 t3.sec=sec+t2.sec;  
 if(t3.sec>60)  
 {  
 t2.min+=1;  
 t3.sec-=60;  
 }  
 t3.min=min+t2.min;  
 if(t3.min>60)  
 {  
 t2.hr+=1;  
 t3.min-=60;  
 }  
 t3.hr=hr+t2.hr;  
 return t3;  
 }  
 void display()  
 {  
 if(hr>=24)  
 { hr=hr%24;  
 }  
 if(hr<10)  
 { cout<<"0"<<hr;  
 }  
 else  
      cout<<hr;  
 if(min<10)  
 { cout<<":0"<<min;  
 }  
 else  
      cout<<":"<<min;  
 if(sec<10)  
 { cout<<":0"<<sec;  
 }  
 else  
      cout<<":"<<sec;  
 }  
 };  
 void main()  
 {  
 clrscr();  
 time c1,c2,c3;  
 cout<<"\n\nEnter the First Time\n\n";  
 c1.read();  
 cout<<"\n\nEnter the Second Time\n\n";  
 c2.read();  
 c3=c1+c2;  
 cout<<"\n\nFirst Time  \t\t";  
 c1.display();  
 cout<<"\n\nSecond Time  \t\t";  
 c2.display();  
 cout<<"\n\nAfter addition,the time is ";  
 c3.display();  
 getch();  
 }  

Vector Addition,Multiplication Program using Vector Class and Operator Overloadingin C++

Classes help to develop easier and effective programming style.To get a better understanding of classes and the concept of abstraction see http://c-madeeasy.blogspot.in/2011/12/what-is-abstractionthe-concept-of.html 

In this program a class named Vector is used to receive data in the form of a vector and + and * operators are overloaded to add and multiply these vectors.The complete Source Code of the C++ program to perform vector addition and multiplication using operator overloading is provided below.

 #include<iostream.h>  
 #include<conio.h>  
 class vector  
 {  
 //Visit c-madeeasy.blogspot.com  
 public:  
 int x,y,z;  
 void read()  
 {  
 cout<<"\n\nEnter the magnitude of i : ";  
 cin>>x;  
 cout<<"\n\nEnter the magnitude of j : ";  
 cin>>y;  
 cout<<"\n\nEnter the magnitude of k : ";  
 cin>>z;  
 }  
 vector operator -()  
 {  
 x=-x;  
 y=-y;  
 z=-z;  
 }  
 vector operator +(vector b)  
 {  
 vector c;  
 c.x=x+b.x;  
 c.y=y+b.y;  
 c.z=z+b.z;  
 return c;  
 }  
 vector operator *(vector b)  
 {  
 int prod;  
 vector c;  
 c.x=x*b.x;  
 c.y=y*b.y;  
 c.z=z*b.z;  
 prod=c.x+c.y+c.z;  
 cout<<"\nScalar Product = ";  
 cout<<prod;  
 vector d;  
 d.x=(y*b.z)-(z*b.y);  
 d.y=(x*b.z)-(z*b.x);  
 d.z=(x*b.y)-(y*b.x);  
 return d;  
 }  
 void display()  
 {  
 cout<<x<<"i"<<"+"<<y<<"j"<<"+"<<z<<"k";  
 }  
 };  
 void main()  
 {  
 vector v1,v2,v3;  
 int choice,cont;  
 do  
 {  
 clrscr();  
 cout<<"\n\tVECTORS\n\n1.Negation of The Vector\n\n2.Sum of Vecors\n\n3.Product of Vectors\n\n";  
 cout<<"\nEnter your choice : ";  
 cin>>choice;  
 switch(choice)  
 {  
 case 1 : cout<<"\nEnter the Vector\n";  
            v1.read();  
            -v1;  
            cout<<"Negation of the Vector : ";  
            cout<<v1.x<<"i"<<v1.y<<"j"<<v1.z<<"k";  
            break;  
 case 2 : cout<<"\n\nEnter the First Vector : ";  
            v1.read();  
            cout<<"\n\nEnter the Second Vector : ";  
            v2.read();  
            v3=v1+v2;  
            cout<<"\n\nThe Sum of Vectors : ";  
            v3.display();  
            break;  
 case 3 : cout<<"\n\nEnter the First Vector : ";  
            v1.read();  
            cout<<"\n\nEnter the Second Vector : ";  
            v2.read();  
            v3=v1*v2;  
            cout<<"\n\nVector Product = ";  
            v3.display();  
            break;  
 default : cout<<"\n\nInvalid Choice";  
 }  
 cout<<"\n\n\nDo you want to continue?(1-YES,0-NO)\n";  
 cin>>cont;  
 }while(cont==1);  
 }  

What is Abstraction?The Concept of Abstraction Simplified.

What is Abstraction in Object Oriented Programming?
Abstraction can be formally defined as the representation of an object including the specification of that object in a certain context.Abstraction is a powerful means to tackle the complexity of programming by wrapping up and thus reducing the complexity of complex operations.

Abstraction is used in OOP(Object Oriented Programming) Languages like Java,C++ etc.These OOP Languages employ an abstract entity called class from which instance of that class called object can be created.Data and Code are Binded together in a syntactic container called Object.

These statements can be little confusing for beginner's so read the rest of the post to get a better view of abstraction.

Abstraction Defined in a Simple way :

The concept of abstraction is a little confusing of beginner's.

To understand the concept of abstraction easily consider a cactus which has lots of spines placed in box.You can easily carry the box without knowing that a cactus is in it.But it is difficult to carry the cactus with bare hands.Thus Abstraction serves as a box to wrap up the complexities.


In programming subprograms are examples of abstractions,as they can be used to perform a function without knowing the internal details.eg: a function named add(int a,int b) can be used to add two integers and produce a result by simply using the code add(1,2) in the program.The internal details of the function that performs addition is not known to the programmer or to the main program.These details are abstracted and this provides a higher level view.


Abstraction simplifies programming as the programmer needs to focus only on the task he has to perform rather that the internal details of the program.Abstraction are provided in Libraries(.dll) for different operations.

Abstraction is implemented commonly in programming languages by using an data type called class.Objects are Instances of a class 

eg:Car is a class Audi,Mercedes etc are Objects of the class named car

 Each Object is an a clone of the an abstraction(class),it posses all the traits of class eg:Mercedes and Audi are two brands of cars but they posses all the characters of a the main class car.Thus they are Objects created from the Abstraction Car.The term Car is used to Abstract or wrap up the internal details like engine,wheels,brakes etc in a single container  named car.



Data Hiding is a Concept of Abstraction by which the Code and the Data in an Object(Instance of an Abstract Data type usually referred to as class) is hidden from the external entities.