simple javascript exercises

I’ve encountered some smaller exercises in the sub-chapters on the fundamentals of JavaScript during my progress in the Web Dev 101 coursework of the Odin Project. I’ve included my solutions here and added the functions that may have usefulness to my functions.js “library” in my scripts repository. These were pretty simple, but I could have constructed some more elegantly with better formatting of my conditional logic. These exercises were a good way to introduce the jasmine JavaScript testing framework. It’s much more efficient to design a battery of tests to check the output of a script than just freestyling something while concurrently feeding it inputs to see if its behaving the way you hope.

const repeatString = function(string, number) {
  if (number < 0) return "ERROR";
  let output = "";
  for (i = 0; i < number; i++) {
    output += string;
  }
  return output;
};

const reverseString = function(string) {
  let array = string.split("");
  let output = array.reverse();
  return output.join("");
};

const leapYears = function(number) {
  if (number % 4 == 0) {
    if (number % 100 == 0) {
      if (number % 400 == 0) {
        return true;
      }
      return false;
    }
    return true;
  }
  return false;
};

const ftoc = function(numFarenheight) {
  numCelsius = (numFarenheight - 32) * (5 / 9);
  return Math.round(numCelsius * 10) / 10;
};

const ctof = function(numCelsius) {
  numFarenheight = numCelsius * (9 / 5) + 32;
  return Math.round(numFarenheight * 10) / 10;
};

const sumAll = function(from, to) {
  sum = 0;
  if (typeof from == "number" && from > 0) {
    if (typeof to == "number" && to > 0) {
      if (from < to) {
        for (i = from; i < to + 1; i++) {
          sum += i;
        }
      } else {
        for (i = to; i < from + 1; i++) {
          sum += i;
        }
      }
    } else {
      return "ERROR";
    }
  } else {
    return "ERROR";
  }
  return sum;
};