getJoinedArrayText

getJoinedArrayText.js

/**
 * Returns array join in a more natural language style by adding commas and 
 * having the last item prefixed with "and".
 * Examples:
 *
 * getJoinedArrayText(['1'])
 * "1"
 * getJoinedArrayText(['1', '2'])
 * "1 and 2"
 * getJoinedArrayText(['1', '2', '3'])
 * "1, 2 and 3"
 * getJoinedArrayText(['1', '2', '3', '4'])
 * "1, 2, 3 and 4"
 * getJoinedArrayText([1,2,3,4,5,6])
 * "6 selected items"
 * getJoinedArrayText([1,2,3,4,5,6], 'items')
 * "6 items"
 */
function getJoinedArrayText(arrayToJoin, manyItemsText) {
  const DISPLAY_LENGTH_TIPPING_POINT = 5;
  var joinedArray = "", arrayLength = arrayToJoin.length;
  if (arrayLength <= DISPLAY_LENGTH_TIPPING_POINT) {
    return arrayToJoin.slice(0, arrayLength - 1).join(', ') +
      (arrayLength > 1 ? " and " : '') +
      arrayToJoin[arrayLength - 1];
  } else {
    return arrayLength + ' ' + ((manyItemsText == null) ? ' selected items' : manyItemsText.trim());
  }
}