为什么我的Javascript代码中的随机数比加起来更串联？

Question

I'm writing a basic random number generator (self teachingvia freeCodeCamp, going to use it for games with my 2 little boys). I'm using a basic HTML with no CSS added as the DOM and Javascript client side for the function (client side as my eldest is 5 and we have a family blog he loves to show people).

The problem is that the code below is working to a point - the Math random function is fine, it works with Math.floor well and the multiplcation * (maximum - minimum +1) is all working as expected.

The issue is that the last segment is not working: + minimum. From the results I have looked at the formula is generating a result up to and including the multiplcation bracked, but then concatenating the minimum on the end, rather than adding it to the result.

I have converted the maximum and minimum values to integers via parseInt when I first discovered the problem, in case there was an issue there (I didn't see why as they both worked fine in the multiplcation bracket), but that of course made no difference.

  function randomNumberFunction(maximum, minimum) { var numRan; var maximum = document.getElementById("maximum").value; var minimum = document.getElementById("minimum").value; parseInt(maximum); parseInt(minimum); numRan = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum; alert(numRan); } 

 <div id="dice"> <form name="randomDice"> <h1>Get a random number</h1> <p>Maximum</p> <input id="maximum" type="number" name="random"><br> <p>Minimum</p> <input id="minimum" type="number" name="random"><br> <br> <button onclick="randomNumberFunction()">Get a random number</button> </form> </div> 

I'm looking to be able to capture the minimum and maximum values a user inputs, and produce a random integer from that range. Instead I get values like 01 when I input min 1, max 4, or 21. or 63 when inputting min 3, max 10.

Answer 1

You aren't assign value when you cast minimum and maximum variables

Try this:

function randomNumberFunction(maximum, minimum) {
  var numRan;
  var maximum = document.getElementById("maximum").value;
  var minimum = document.getElementById("minimum").value;
  maximum = parseInt(maximum);
  minimum = parseInt(minimum);

  numRan = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
  alert(numRan);
}