C Program for Prime Number Using Recursion

Sulaiman Aminu Barkindo — Thu, 06 Oct 2022 03:32:27 +0000

Introduction
Prime number is a number that is greater than 1 and can be divided only by 1 or itself. In other words, prime numbers can't be divided by numbers other than itself or 1. Example of prime numbers are 2, 3, 5, 7, 11, ...

Implementation
I made the implementation in two functions to aid readability.

/**
 * is_prime - detects if an input number is a prime number.
 * @n: input number.
 * @i: iterator.
 * Return: 1 if n is a prime number. 0 if n is not a prime number.
 */
int is_prime(unsigned int n, unsigned int i)
{
        if (n % i == 0)
        {
                if (n == i)
                        return (1);
                else
                        return (0);
        }
        return (0 + is_prime(n, i + 1));
}
/**
 * is_prime_number - detects if an input number is a prime number.
 * @n: input number.
 * Return: 1 if n is a prime number. 0 if n is not a prime number.
 */
int is_prime_number(int n)
{
        if (n <= 1)
                return (0);
        return (is_prime(n, 2));
}

is_prime_number

make the first check that the number supplied is not 1 or less than 1 as prime numbers only start from 2 upward. Then call

is_prime

to finish the check if the function is a prime number.

Final Thoughts
This is my implementation of C program to check prime number, feel free to give your thoughts in the comment section.

How to Rename a Field in Mongoose with Example

Sulaiman Aminu Barkindo — Sun, 11 Sep 2022 22:14:42 +0000

Introduction
Sometimes you may want to change the name of a field in your Schema for different reasons. If you are using mongoose performing only $rename operation may not work for you. In this article, you will see how to achieve renaming a field in mongoose in three (3) easy steps.

Let's Dive In
Assuming we have this user schema
{ firstName: String, surname: String, username: String }
and we have documents in the collection
[ { "_id": ObjectId("5a934e000102030405000000"), "firstName": "Sulaiman", "surname": "Aminu", "username": "souley" }, { "_id": ObjectId("5a934e000102030405000001"), "firstName": "Alice", "surname": "Bob", "username": "Aladin" } ]
we want to rename the field surname to lastName

Step 1: Add the New field Name in the Schema
To rename a field you need to first add the name you want the field to become in your schema.
{ firstName: String, surname: String, // leave this for now lastName: String, // this is the added field username: String }

Step 2: Rename the Field using $rename
we can use the following code to rename the field.
db.collection.updateMany({}, { $rename: { "surname": "lastName" } } )

Now the documents will look like this
[ { "LastName": "Aminu", "_id": ObjectId("5a934e000102030405000000"), "firstName": "Sulaiman", "username": "souley" }, { "_id": ObjectId("5a934e000102030405000001"), "firstName": "Alice", "lastName": "Bob", "username": "Aladin" } ]

Step 3: Remove the old Field Name if You Want to
Now, we can safely delete the old field name from our schema if we don't need it anymore.
{ firstName: String, surname: String, // you can remove this now lastName: String, username: String }

In Conclusion
To rename a field in mongoose you will need to add the new field in the schema, rename the field with $rename operator, and lastly, delete the field from your schema if you want to.

More Info on $rename

mongodb.com

DEV Community: Sulaiman Aminu Barkindo

C Program for Prime Number Using Recursion

How to Rename a Field in Mongoose with Example