function plusFn(l, r) {
	if (typeof l === "undefined") return r;
	if (typeof r === "undefined") return l;
	return l + r;
}
The software constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.