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JavaScript JavaScript Functions Arrow Functions Testing for Number Arguments

Jamie Davies
Jamie Davies
2,787 Points
Posted by Jamie Davies
Jamie Davies
2,787 Points

IS this an OK solution?

const lower = parseInt(prompt('Type in a low number.'));
const upper = parseInt(prompt('Type in a high number.'));

const getRandomNumber = (lower, upper) => {  
    if (isNaN(lower && upper)) {
      throw Error("This isn't a number reload the page and start again");
    }
  return Math.floor(Math.random() * (upper - lower + 1)) + lower;
}

document.write(`Your low number is ${lower} and your high number is ${upper}.<br> 
A random number between both of these is ${getRandomNumber(lower, upper)}`);

1 Answer

rydavim
rydavim
18,814 Points
rydavim
rydavim
18,814 Points

Looks pretty good, nice job!

I would note is that you're not catching the edge case if someone puts in one number and one string.

if (isNaN(lower && upper)) { // Fails if both entries are strings, but not if only one is.
  throw Error("This isn't a number reload the page and start again");
}

You'll want to check to see if the lower number or the upper number aren't integers.

The other very minor thing is that it's possible to get a random number that is the same as the upper number. I don't know whether you intend this or not, but it's something to investigate if you wanted an extra challenge.

But you're doing great, keep up the good work and happy coding!

Jamie Davies
Jamie Davies
2,787 Points
Jamie Davies
Jamie Davies
2,787 Points

Thanks for your feedback, much appreciated!

if (isNaN(lower && upper)) { // Fails if both entries are strings, but not if only one is.
  throw Error("This isn't a number reload the page and start again");
}

When using this code it throws an error if both are strings and if only one of the inputs is a string which is what is intended in the challenge i thought. I have tried to use the OR || operator and that allows the function to run with one input as a string or I am not grapsing something here?

No i never intended for that to happen but i will have a look into it and see if I can do that as an extra challenge :)

Thanks

Kirt Perez
Kirt Perez
7,374 Points

Jamie Davies, having one argument as a string going into that if statement would not throw the error.