text: function filter_list(l) {
      let newArray = [];
      for (let i = 0; i < l.length; i++) {
          if (typeof l[i] === "number" && l[i] >= 0) {
              newArray.push(l[i]);
          }
      }
      console.log(newArray);
      return newArray;
  }
  filter_list([1, 2, 'a', 'b']);