Create a Phone Number

With the intense pacing and curriculum of bootcamp over, it's time to tackle daily coding challenges to stay fresh.

Codewars it is!

The first challenge:

Write a function that accepts an array of 10 integers (between 0 and 9),
that returns a string of those numbers in the form of a phone number.

Example:

createPhoneNumber([1, 2, 3, 4, 5, 6, 7, 8, 9, 0]) // => returns "[phone]"

My deer-in-headlights expression (I haven't joined and sliced in a few weeks) faded as soon as I started pseudo coding and breaking this up into small pieces.

First. This is an array of numbers, all separated by commas, and it needs to look like a phone number. Which means, we need to slice as a way of selecting and then grouping certain numbers together.

Big thanks to w3schools for refreshing my memory!

The slice() method returns the selected elements in an array, as a new array object.

It selects the elements starting at the given start argument, and ends at, but does not include, the given end argument. Syntax looking like so:

array.slice(start, end)

In this case:

numbers.slice(0, 3)
numbers.slice(3, 6)
numbers.slice(6)

To accompany slice(), join() method returns the array as a string - which we need in order to return the phone number as a string.

Because our array of numbers is separated by a specified separator (fancy speak for a comma), we need to join the numbers into the beginnings of a phone number.

This also means we need to use .slice AND .join methods to take out the values we need from the array, between the specified indexes, and group them together:

numbers.slice(0, 3).join('')
numbers.slice(3, 6).join('')
numbers.slice(6).join('')

Three more things.

We can use string template literals to clean up our code. But we'll also need to add parentheses around the first slice/join statement, and a dash before the final four numbers:

function createPhoneNumber(numbers) {
    return `(${numbers.slice(0, 3).join('')}) ${numbers.slice(3, 6).join('')}-${numbers.slice(6).join('')}`;
}

And this will return our (xxx) xxx-xxxx phone number!

After reading through the alternate solutions from other Codewar users, I was astounded at the variety that exists. Code can be so versatile (lovely!) but this can make being a newbie intimidating (feelin' that!).

Always learning and looking forward to the next challenge.

In case you made it all the way here and you have your own solution, I'd love to see it!