# C++ program to print prime numbers upto n

In this program, we are going to print prime numbers in c++ using the following methods:

• Prime numbers upto n
• Prime numbers between 1 to 100
• Prime numbers in a given range

Basic knowledge required: for-loop & if-else.

## C++ program to print prime numbers upto n

We have to print prime numbers from 1 to n where n is upper range. The upper range is given by the user according to his/her choice.

```#include<iostream> using namespace std; int main() {     int n,i,j;     cout<<"Enter upper range:";     cin>>n;     cout<<"\n Prime Numbers from 1 to "<<n<<": ";     for(i=1;i<=n;i++)     {         for(j=2;j<=i;j++)         {              if(i%j==0)             break;         }     if(i==j)     cout<<j<<" ";     } return 0; }
```

Output:
Enter upper range:50
Prime Numbers from 1 to 50: 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 ## C++ program to print prime numbers between 1 to 100

In this program, we have to print prime numbers from 1 to 100.

`#include<iostream> using namespace std; int main() {     int i,j;     cout<<"\n Prime Numbers from 1 to 100: ";     for(i=1;i<=100;i++)     {         for(j=2;j<=i;j++)         {             if(i%j==0)             break;         }     if(i==j)     cout<<j<<" ";     } return 0; }`
Output:
Prime Numbers from 1 to 100: 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97

## C++ program to print prime numbers in a given range

In this program, we have to display prime numbers in a given range i.e., lower limit to upper limit. The lower limit, as well as the upper limit, is given by the user according to his/her choice.

`#include<iostream>using namespace std;int main(){    int l,u,i,j;    cout<<"Enter lower limit:";    cin>>l;    cout<<"Enter upper limit:";    cin>>u;    cout<<"\n Prime Numbers from "<<l<<" to "<<u<<": ";    for(i=l;i<=u;i++)    {        for(j=2;j<=i;j++)        {            if(i%j==0)            break;        }    if(i==j)    cout<<j<<" ";    }return 0;} `
Output:
Enter lower limit:10
Enter upper limit:50
Prime Numbers from 10 to 50: 11 13 17 19 23 29 31 37 41 43 47 