A prime number is an integer greater than 1 that is evenly divisible by only 1 and itself. For example, the number 5 is prime because it can only be evenly divided by 1 and 5. The number 6, however, is not prime because it can be divided by 1, 2, 3, and 6. Write a Boolean function named isPrime, which takes an integer as an argument and returns true if the argument is a prime number, and false otherwise.

I am writing a C++ program.    

bool isPrime(int integer)  //boolean function that takes integer argument //and returns true if argument is prime number otherwise false

{  if (integer > 1)  // if the integer value is greater than 1

{   for (int i = 2; i <= integer; ++i)  

//loop starts from 2 and iterates until the value of i gets greater than integer //value

 {  if (integer % i == 0)  // if integer value is completely divisible by i

 {    if(integer == i)  // if integer value is equal to i

   return true;  //function returns true

   else     //if integer value is not divisible by i

   return false;  //function returns false } } } }  }

Explanation:

In order to see the output of the program you can write a main() function as following:

int main()  {  //start of the main() function body

int integer;    // int type variable integer

cout<< "Enter an integer:  ";  //prompts user to enter an integer value

 cin  >> integer;   //reads the input from user

cout << integer<<" ";   //prints the integer value entered by user

if (isPrime(integer))  

// calls boolean function to check if the integer value is prime number or not

{  cout << " is a Prime number." << endl;   }

//displays the message number is prime

else  //if the integer value is not prime

 cout << " is not a Prime number." << endl;  }  //displays message

The output along with the program is attached as screenshot.