classnames/index.js

/*!
  Copyright (c) 2015 Jed Watson.
  Licensed under the MIT License (MIT), see
  http://jedwatson.github.io/classnames
*/

function classNames() {
	var classes = '';
	var arg;

	for (var i = 0; i < arguments.length; i++) {
		arg = arguments[i];
		if (!arg) {
			continue;
		}

		if ('string' === typeof arg || 'number' === typeof arg) {
			classes += ' ' + arg;
		} else if (Object.prototype.toString.call(arg) === '[object Array]') {
			classes += ' ' + classNames.apply(null, arg);
		} else if ('object' === typeof arg) {
			for (var key in arg) {
				if (!arg.hasOwnProperty(key) || !arg[key]) {
					continue;
				}
				classes += ' ' + key;
			}
		}
	}
	return classes.substr(1);
}

// safely export classNames for node / browserify
if (typeof module !== 'undefined' && module.exports) {
	module.exports = classNames;
}

// safely export classNames for RequireJS
if (typeof define !== 'undefined' && define.amd) {
	define('classnames', [], function() {
		return classNames;
	});
}