Strangely a variable is not defined on the same line, even though it was used earlier on the line.

// Collect input from a user
var userLowInput = prompt("Give me a low number");
var userHighInput = prompt("Give me a high number");

//console.log(`1) ${userLowInput}`);

if(userLowInput && userHighInput){
  // Convert the input to a number
  const userlowInt = parseInt(userLowInput);
  const userHighInt = parseInt(userHighInput);

  //console.log(`2) ${userInt}`);

  // Use Math.random() and the user's number to generate a random number
  var randomNum = Math.floor(Math.random() * (userHighInt - userlowInt+1) ) + userLowInt;
  console.log(`3) ${randomNum}`);

  // Create a message displaying the random number
  console.log(`${randomNum} is the random number between ${userLowInt} and ${userHighInt}`);
}else {
  console.log(`You need to add a number`);
}