---
layout: docs
title: addParameter
id: class.Facebook.HackCodegen.CodegenFunctionish.addParameter
docid: class.Facebook.HackCodegen.CodegenFunctionish.addParameter
permalink: /docs/reference/class.Facebook.HackCodegen.CodegenFunctionish.addParameter/
---
# Facebook\\HackCodegen\\CodegenFunctionish::addParameter()




``` Hack
public function addParameter(
  string $param,
): this;
```




## Parameters




+ ` string $param `




## Returns




* ` this `