Joins a string of characters together in a string.

joinList

/*
 * Write a function that joins the contents of conceptList together
 * into one String, concepts, with each list item separated from
 * the previous by a comma.
 *
 * To implement this we'll create a joinList function which will take 
 * in any array of strings return a comma-separated string.
*/

let joinList = function(list) {
  let str = "";
  for (let i = 0; i <= list.length - 1; i++) {
    for (let j = 0; j <= list[i].length - 1; j++) {
      str += list[i][j];
    }
    if (i !== (list.length - 1)) {
      str += ", ";
    }
  }
  return str;
};

console.log(`Today I learned about ${joinList(["gists", "types", "operators", "iteration", "problem solving"])}.`);