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JavaScript JavaScript Basics (Retired) Working With Numbers The Random Challenge Solution

Posted by Norbert Stadler
Norbert Stadler
4,015 Points

My solution

So I faced some problems when I was writing the code:

1) What if the first given number is greater than the second? For this, I wrote an "if" statement (see below). 2) When I tried with two adjacent integers, I always got the greater number. I tried with 54 and 55 and always got 55 because of the floor and +1 method. I came up with this:

var numberX = prompt('Random number between x and y. Give the x number:'); numberX = parseInt(numberX); var numberY = prompt('Give the y number:'); numberY = parseInt(numberY);

if (numberX > numberY) { numberZ = numberX numberX = numberY numberY = numberZ }

alert(Math.round(Math.random() * (numberY - numberX) + numberX));

What do you think?

Mark VonGyer
Mark VonGyer
21,239 Points
Mark VonGyer
Mark VonGyer
21,239 Points

it's quite inefficient to create these additional numbers and move the storage around.

What might be better is if you wrote the function line twice and changed it.

if(numberX > numberY){

function 1;

}else {

function 2(which is the reverse of function 1); }

It might mean more code but it definitely makes processes faster for the client.

1 Answer

Andrei Fecioru
Andrei Fecioru
15,059 Points
Andrei Fecioru
Andrei Fecioru
15,059 Points

Hi,

You can also do something like this:

var a = Math.min(numberX, numberY);
var b = Math.max(numberX, numberY);

alert(Math.round(Math.random() * (b - a) + a));

But then again I would view this as a scenario where the input data is invalid. If I were to write a function which generates a random integer between two input integers I would do something like:

function generateRandInt(start, end) {
    start = parseInt(start);
    end = parseInt(end);

    // check the input values.
    if (isNaN(start) || // the start value is invalid
        isNaN(end) || // the end value is invalid
        (start >= end)) // the start value is not greater than the end value 
    {
         // abort the computation
         throw new Error("Invalid input arguments");
    }

    // do the processing
    return Math.round(Math.random() * (end - start) + end);
}

That would be my take on this.