How to add two numbers in C++
In this short tutorial, I will show you adding two numbers in C++.
- First program: Adds two variable values
- Second Program: User is asked to enter two numbers to get the sum
- Third Program: Class is used with two functions to add user entered two numbers
- and more
C++ First program to add to variable values
- We have three variables i, j, and sum
- Variable i and j are assigned int values
- The next line adds the values of variable i and j and their toal is assigned to variable sum.
The code:
#include <iostream>
using namespace std;
int main() {
int i, j, sum;
i = 50;
j = 75;
sum = i + j;
cout << sum;
cout << "Sum of Two Numbers = " << sum;
return 0;
}
Taking user input and adding two numbers program
In this program:
- We ask the user to enter two int numbers
- We assigned the entered numbers to two variables i and j
- The values of two variables are added and the sum is assigned to the variable sum
The code:
#include <iostream>
using namespace std;
int main() {
int i, j, sum;
cout << "Please enter two numbers\n ";
cin >> i >> j; //Taking user input
sum = i+ j;
// prints sum
cout << "Sum of Two Numbers = " << sum;
return 0;
}
Adding two real numbers program
The following program adds two real numbers (float) after taking the user input.
- We declared three variables of float type
- Ask the user to enter two real numbers
- Get the sum and display it on the screen
The program
#include <iostream>
using namespace std;
int main() {
float i, j, sum; //Declaring three float variables
cout << "Please enter two real numbers\n ";
cin >> i >> j; //Taking user input for real numbers
sum = i+ j;
// prints sum
cout << "Sum of Two float Numbers = " << sum;
return 0;
}
Sample Output:
Using a function to add two numbers
Let us add two numbers while tasting how to write a simple function in C++.
- Again, we will take two numbers as input from the user
- The numbers are sent to the function (sumFunc)
- The sumFunc function returns the sum of those two numbers
- We will finally display the sum of two numbers on the screen
The code:
#include<iostream>
using namespace std;
int SumFunc(int, int);
int main()
{
int i, j, sum;
//Asking user to enter numbers
cout<<"Please enter two int numbers: \n";
cin>>i>>j;
//Calling the SumFunc function
sum = SumFunc(i, j);
cout<<"The Sum of Two float Numbers = "<<sum;
return 0;
}
int SumFunc(int x, int y)
{
return (x+y);
}
A sample output:
Using C++ Class to add two numbers
You might get the assignment to write a simple class in C++ for adding two numbers. So, I will show you how you can do it easily.
The code:
#include <iostream>
using namespace std;
class SumCls {
int i, j;
public:
void enterNum() {
cout << "Please enter two numbers\n";
cin >> i >> j;
}
void getSum() {
cout << "Sum of Two Numbers = " << i + j;
}
};
int main()
{
SumCls m;
m.enterNum();
m.getSum();
return 0;
}
A sample of the above code:
So what is in the code?
- We created a class namely SumCls()
- A function, enterNum is created in the class to take user input
- The user entered two numbers that are assigned to i and j variables
- A second function getSum() is created to add these two numbers
- We also displayed the sum of two numbers in that function
- In the main body, we simply called those two functions
Sum of two numbers with an array example
In this program,
- We created an array of three elements
- First two elements are assigned two int numbers that we want to get the sum
- Third element stores the sum of the first two elements
- We display the result i.e. third element
The program:
#include <iostream>
using namespace std;
int main() {
int arrSum[3]; //Declaring an int type array of 3 elements
arrSum[0]=10;
arrSum[1]=20;
arrSum[2]=arrSum[0] + arrSum[1];
//Display result
cout<<"Sum of "<<arrSum[0]<<" and "<<arrSum[1]<<" is \n"<<arrSum[2];
return 0;
}
Output:
