intersection.js
export default function intersection(array) { var result = []; var argsLength = arguments.length; for (var i = 0, length = getLength(array); i < length; i++) { var item = array[i]; if (contains(result, item)) continue; var j; for (j = 1; j < argsLength; j++) { if (!contains(arguments[j], item)) break; } if (j === argsLength) result.push(item); } return result; }