////////////////////////////////////
// Core Methods for Week 0
////////////////////////////////////
var repeatNumbers = function(data) {
  if (!data || data.length === 0) {
    // Invalid inputs
    // console.log("Data input is null or length = 0");
    return "";
  }
  let num_strings = [];
  for (let num_pair of data) {
    if (!(num_pair instanceof Array || num_pair.length === 2)) {
      // console.log("Num_pair is not an array or not length 2");
      return "";
    }
    //In case String was passed in
    let num = Number(num_pair[0]);
    let repeat = Number(num_pair[1]);
    let numberStr = "";
    for (let i = 0; i < repeat; i++) {
      numberStr += num;
    }
    num_strings.push(numberStr);
  }
  return num_strings.join(", ");
};

var runTask1 = function() {
  console.log(repeatNumbers([[1, 2]]));
  console.log(repeatNumbers([[1, 10]]));
  console.log(repeatNumbers([[1, 2], [2, 3]]));
  console.log(repeatNumbers([[10, 4], [34, 6], [92, 2]]));

  /*
Expected Output
1111111111
11, 222
10101010, 343434343434, 9292
*/
};

runTask1();