code: function contains(array, value) {
    for (let i = 0; i < array.length; i++) {
      if (array[i] == value) { // non-strict equality check!
        return true;
      }
    }
    return false;
  }
docs: Check whether an array contains some value.
  Uses a non-strict comparison, so contains([1,2,3], '2') returns true
  @param {Array} array
  @param {*} value
  @return {boolean}