# Rust program to check a given number is prime or not using recursion

Rust | Checking Prime Number Example: Given a number, we have to check whether it’s a prime number or not using recursion.
Submitted by Nidhi, on October 11, 2021

Problem Solution:

In this program, we will create a recursive function to check a given number is prime or not using recursion.

Program/Source Code:

The source code to check a given number is prime or not using recursion is given below. The given program is compiled and executed successfully.

```// Rust program to check a given number
// is prime or not using recursion

fn checkPrime(num:i32, i:i32)->i32{
if (i == 1){
return 1;
}
else{
if (num % i == 0)
{
return 0;
}
else
{
return checkPrime(num, i - 1);
}
}
}

fn main() {
let num:i32=11;
let rs = checkPrime(num,num/2);

if rs == 1
{
println!("{} is a prime number.", num);
}
else
{
println!("{} is not a prime number.", num);
}
}
```

Output:

```11 is a prime number.
```

Explanation:

In the above program, we created two functions checkPrime() and main(). The checkPrime() function is a recursive function, which is used to check a given number is prime or not and return the result to the calling function.

In the main() function, we called the checkPrime() function and printed the result.