2D Arrays Issue

1

Hey guys,

I’m working on the “Smallest Common Multiple” problem, and my solution involves creating an array of arrays to store the factors of each number. My issue is that no matter what I do, all the numbers get bunched up into a single array instead. Here’s my code, see the “???” comment.

function smallestCommons(arr) {
  
  var arr2 = [];
  var primes = [];
  
  // Sort the arguments in ascending order
  arr.sort();
  
  // Fill out the missing values
  for (i = arr[0]; i <= arr[1]; i++) {
    arr2.push(i);
  }
  
  console.log("arr2: " + arr2);
  
  // Iterate through array and factorize each value
  for (i = 0; i < arr2.length; i++) {
    console.log("num: " + arr2[i]);
    // Sub-array for factorized numbers of current value
    var primeSlice = [];
    // Initial value, then remainder until empty
    var x = arr2[i];
    // Ignore 1
    if (x !== 1) {
      // Factorize
      for (var y = 2; y <= x; y++) {
        while (x % y === 0) {
          primeSlice.push(y);
          x /= y;
        }
      }
    }
    // If 1 push 0
    else {
      primeSlice.push(0);
    }
    console.log("primeSlice: " + primeSlice);
    // Create new sub array at i
    primes[i] = [];
    // ???
    primes[i].push([primeSlice]);
  }
  
  console.log("primes: " + primes);
  console.log("===========");
  
  return arr;
}

smallestCommons([1,5]);

I’ve tried every way I can think of and it always gives me “0,2,3,2,2,5” in the console, instead of “[0], [2], [3], [2, 2], [5]” for 1 to 5. What am I doing wrong?

Thanks.

2

If you used console.log("primes: " + JSON.stringify(primes)); you’ll see that you actually have more brackets than what you expected.

primes: [[[[0]]],[[[2]]],[[[3]]],[[[2,2]]],[[[5]]]]

2 Likes
3

Damn, I could of swore I saw a proper tree structure in the console before but it must of been an object now that I think about it. Thank you so much.