9 basic program in cpp programming language

1. Write a c++ program to print the “Hello world!”

#include<iostream>
    
    using namespace std;
    
    int main(){
        cout<<"Hello World!";
        return 0;
    }

2. Write a c++ program add two numbers

#include<iostream>
    using namespace std;
    
    int main(){
        
        int n1, n2;
        cout<<"Enter the number 1 : ";
        cin>>n1;
        cout<<"Enter the number 2 : ";
        cin>>n2;
        
        int add = n1 + n2;
        cout<<"The sum of "<<n1<<" and "<<n2<<" is : "<<add<<endl;
        return 0;
    }

3. Write a c++ program to explain cascading of insertion (<<) operator and cascading of Extraction (>>).

#include<iostream>
    
    using namespace std;
    
    int main(){
        int n1, n2;
        cout<<"Enter two numbers : ";
        cin>>n1>>n2;
        int sub = n1 - n2;
        cout<<"\n"<<n1<<" - "<<n2<<" = "<<sub<<endl;
        return 0;
    }

4. Write a c++ program print the lapmos.com but in the program also write “Hello world, Welcome to lapmos.com" but do not execute this statement.

#include<iostream>
    
    using namespace std;
    
    int main(){
        
        // Hello World, welcome to lapmos.com
        cout<<"lapmos.com";
        return 0;
    }

5. Write a c++ program to print “Hello world!” and each print in a new line 5 times.

#include<iostream>
    
    using namespace std;
    
    int main(){
    
        cout<<"Hello World"<<endl;
        cout<<"Hello World"<<endl;
        cout<<"Hello World"<<endl;
        cout<<"Hello World"<<endl;
        cout<<"Hello World"<<endl;
        return 0;
    }

6. Write a program using setw() as an example.

#include<iostream>
    #include<iomanip>
    
    using namespace std;
    
    int main(){
    
        cout<<setw(10)<<"lapmos"<<endl;
        cout<<setw(10)<<"lapmos.com"<<endl;
        return 0;
    }

7. Write a c++ program swap to numbers using third variable.

#include<iostream>
    
    using namespace std;
    
    int main(){
    
        int n1, n2, temp;
        cout<<"Enter two Numbers : ";
        cin>>n1>>n2;
        
        cout<<"Before Swapping : n1 = "<<n1<<" and n2 = "<<n2<<endl;
       
        temp = n1;
        n1 = n2;
        n2 = temp;
       
        cout<<"After Swapping : n1 = "<<n1<<" and n2 = "<<n2<<endl;
        return 0;
    }

8. Write a c++ program swap two number without using third variable.

#include<iostream>
    
    using namespace std;
    
    int main(){
    
        int n1, n2, temp;
        cout<<"Enter two Numbers : ";
        cin>>n1>>n2;
        
        cout<<"Before Swapping : n1 = "<<n1<<" and n2 = "<<n2<<endl;
       
        n1 = n1 + n2;
        n2 = n1 - n2;
        n1 = n1 - n2;
       
        cout<<"After Swapping : n1 = "<<n1<<" and n2 = "<<n2<<endl;
        return 0;
    }

9. Write a c++ program to print the value from 1 to 100.

#include<iostream>
    
    using namespace std;
    
    int main(){
       
        for(int i = 1; i<=100; i++){
            cout<<i<<" ";
        }
        return 0;
    }