Random Number Challenge - My Solution

This took me a while, as math isn't my strong suit. I had to look up a couple of things that haven't yet been covered in these lessons, but I figure that's sort of the point as well, right?

Anyway. I opted for the extra challenge to input 2 numbers.

var firstNumber = prompt("Give us a number...");
var secondNumber = prompt("And another...");

firstNumber = parseInt(firstNumber);
secondNumber = parseInt(secondNumber);

I wasn't sure if it was important to first figure out which is the higher number, otherwise we might end up with negative values. So I found Math.min and Math.max.

//which is lower?
var lowestNumber = Math.min(firstNumber,secondNumber);

//which is higher?
var highestNumber = Math.max(firstNumber,secondNumber);

To test this was working, I used console.log.

console.log("Lowest number is: " + lowestNumber);
console.log("Highest number is: " + highestNumber);

This was where it got tricky for me. I basically had to look this up, as I couldn't brain it with my own brain.

var randomNumber = Math.floor(Math.random() * (highestNumber - lowestNumber + 1 )) + lowestNumber;

So, basically, generate the random number using Math.random, and multiply that by the highest number minus the lowest number + 1. Then add the lowest number, to ensure that the final result doesn't go under the lowest given value.

So it would look like this:

random Number * (high - low + 1) + low

or, as a simple example...

0.5 * (100 - 50 + 1) + 50

further broken down as...

0.5 * 51 + 50 = 75.5

Then Math.floor that sucker, giving us 75.

Interestingly, I had to store this result in its own variable (randomNumber), since if I placed the math statement directly in the alert it was treated as a string, appending onto the end of the alert message.

alert("Here's a number between  " + lowestNumber + " and " + highestNumber + ": " + randomNumber);

Not sure why this is, but it was probably a good thing anyway as it helped keep my code a bit more manageable and readable.