- C++ Program to Check Prime Number Using User-defined Function
C++ Program to check prime numbers using function
#include<iostream>
using namespace std;
int isPrime(int num);
int main() {
int num;
cout << "Enter a positive number\n";
cin >> num;
if(isPrime(num))
cout << num << " is a Prime Number",num);
else
cout << num <<" is NOT a Prime Number",num);
return 0;
}
// returns 1 if num is prime number otherwise 0
int isPrime(int num){
int i;
// Check whether num is divisible by any
// number between 2 to (num/2)
for(i = 2; i <=(num/2); ++i) {
if(num%i==0) {
return 0;
}
}
return 1;
}
Output
Enter a positive number 23 23 is a Prime Number
Enter a positive number 50 50 is NOT a Prime Number
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