Generate a Random Number between 2 values to 2 decimals places in Javascript

Question

I want to generate a random number between 1 and 10 up to 2 decimal places,

I'm currently using this below to generate my numbers,

var randomnum = Math.floor(Math.random() * (10.00 - 1.00 + 1.00)) + 1.00; 

Ultimately, I would like to know how to generate numbers like:

1.66

5.86

8.34

In the format: var randomnum = then the code

sidenote: I don't remember why I previously had generated my numbers like that but remember something about Math.random generating numbers to 8 decimal places.

Thank you for the help! :)

Ps: I've seen a lot of posts about waiting to round down or up generated numbers and haven't found one wanting to generate them straight out.

UPDATE: I want a number value not a string that looks like a number

Answer 1

You were very close, what you need is not to work with decimal numbers as min and max. Let's have max = 1000 and min = 100, so after your Math.floor you will need to divide by 100:

var randomnum = Math.floor(Math.random() * (1000 - 100) + 100) / 100; 

Or if you want to work with decimals:

var precision = 100; // 2 decimals var randomnum = Math.floor(Math.random() * (10 * precision - 1 * precision) + 1 * precision) / (1*precision); 

Answer 2

Multiply the original random number by 10^decimalPlaces, floor it, and then divde by 10^decimalPlaces. For instance:

floor(8.885729840652472 * 100) / 100  // 8.88 

function genRand(min, max, decimalPlaces) {        var rand = Math.random()*(max-min) + min;      var power = Math.pow(10, decimalPlaces);      return Math.floor(rand*power) / power;  }    for (var i=0; i<20; i++) {    document.write(genRand(0, 10, 2) + "<br>");  }

Edit in response to comments:
For an inclusive floating-point random function (using this answer):

function genRand(min, max, decimalPlaces) {       var rand = Math.random() < 0.5 ? ((1-Math.random()) * (max-min) + min) : (Math.random() * (max-min) + min);  // could be min or max or anything in between     var power = Math.pow(10, decimalPlaces);     return Math.floor(rand*power) / power; }