Compare software release version

verscmp.js

/* E.g. verscmp("1.2.3", "1.2.2") */
function verscmp(a, b) {
	var spa = a.split('.').map(x => Number(x));
	var spb = b.split('.').map(x => Number(x));
	var part = [], r = 0;

	while(!r && spa.length && spb.length) {
		part = [spa.shift(), spb.shift()];
		if(part[0] == part[1])
			continue;
		r = part[0] > part[1] ? -1 : 1;
		break;
	}
	if(!r && (spa.length || spb.length)) {
		/* ignore any leading zeros, e.g. 0.1 == 0.1.0 */
		spa = spa.filter(x => x);
		spb = spb.filter(x => x);
		if(spa.length || spb.length)
			return spa.length ? -1 : 1;
	}
	return r;
}