Smallest Common Multiplier - trying to use .every() without success

#1

I’m trying to solve the Smallest Common Multiplier challenge using the code below, but I can’t understand why it’s not working.

If I set count to 60 when I declare it, test will evaluate to true, but when i increment count up from 2 in the while loop it continues past 60 until I get a ‘potential infinite loop’ warning. Why is this?

Any help would be appreciated.

function smallestCommons(arr) {
  
  var range = [];
  var count = 2;
  var result = 0;
  
  //push to range array
  for(var i = arr[0]; i <= arr[1]; i++){
    range.push(i);
  }

  //check if every element in arr is divisible
  var test = range.every(function(el) {
    return count % el === 0;  
  });
  

  while(test === false) {
    count++;
    console.log(count);
  }
  
return count;
  
}


smallestCommons([1, 5]);
#2

If you set count to 60 your .every() function evaluates to true, while loop never runs and you just return count.

If you set count to 2 .every() evaluates to false (2 % 5 !== 0) and your while loop starts running, but never exits (test doesn’t change);

#3

Thanks - not sure how I missed that one!

#4

I now have the following - which works (sort of) for the first 4 criteria, but won’t pass the 5th, presumably because counting all the way up to 6056820 is a ridiculously inefficient way of doing this. I’m stuck for other ideas now though.

Edit: actually it did pass. This can’t be a good way to solve this problem though, right?

//  
function smallestCommons(arr) {
  
  var highest = Math.max.apply( Math, arr );
  var lowest = Math.min.apply( Math, arr );
  
  var range = [];
  var count = 2;
  var result = 0;
  
  //push to range array
  for(var i = lowest; i <= highest; i++){
    range.push(i);
  }

  
    var modulo = function(el) {
    return count % el === 0;  
  };
  //check if every element in arr is divisible
  var test = range.every(modulo);
  

  

  while(test === false) {
    count++;
    test = range.every(modulo);
    
    if (count > 6056820) {
      break;
    }
  }
  
return count;
  
}


smallestCommons([23, 18]);
#5

Do you really need to make checks for every number in the range?