```diff export default function () { - var i=0, tmp, x, str=''; + var tmp, x, len=arguments.length, str='', i=0; - while (i < arguments.length) { + while (i < len) { if (tmp = arguments[i++]) { if (x = toVal(tmp)) { str && (str += ' '); str += x } } } return str; } ```

Benchmark on only string concatenation shows an increase of about 1,000,000 operation/sec. **Note:** I got benchmark results only in node, in a really inaccurate way. but theoretically, it must increase the performance.