Program to check whether a number is a prime number or not using the function.

Here, we have a basic program example to check if the number is prime or not with functions using different languages. This program is created in c language, c++, Java, and Python.

Function to check if the number is prime in C language

#include<stdio.h>
int PrimeOrNot(int);
int main()
{
    int n1,prime;
    printf(" Enter a positive number : ");
    scanf("%d",&n1);
    prime = PrimeOrNot(n1);
   if(prime==1)
        printf(" The number %d is a prime number.\n",n1);
   else
      printf(" The number %d is not a prime number.\n",n1);
   return 0;
}
int PrimeOrNot(int n1)
{
    int i=2;
    while(i<=n1/2)
    {
         if(n1%i==0)
             return 0;
         else
             i++;
    }
    return 1;
}

Function to check if the number is prime in C++ language

#include <iostream>
using namespace std;
bool isPrime(int num);
int main(){
   int num;
   bool flag;
   cout<<"Enter any positive number: ";
   cin>>num;
   flag = isPrime(num);
   if (flag==true)
      cout<<num<<" is a prime number";
   else
      cout<<num<<" is not a prime number";
   return 0;
}
bool isPrime(int num){
    bool flag=true;
    for(int i = 2; i <= num / 2; i++) {
       if(num % i == 0) {
          flag = false;
          break;
       }
    }
    return flag;
}

Function to check if the number is prime in Python language

num = int(input("Enter a positive integer: "))
def checkPrime(num):
    if(num <= 1):
        return False
    for i in range(2,num):
        if(num % i)==0:
            return False
    return True
if(checkPrime(num)):
    print(num," is a Prime number.")
else:
    print(num," is not a prime number.")