<li><ahref="#app.router">app.router</a></li>

<li><ahref="#req.body">req.body</a></li>

<li><ahref="#req.host">req.host</a></li>

<li><ahref="#req.params">req.params</a></li>

<li><ahref="#req.query">req.query</a></li>

<li><ahref="#res.clearCookie">res.clearCookie</a></li>

<li><ahref="#res.status">res.status</a></li>

The`app.router` object, which was removed in Express 4, has made a comeback in Express 5. In the new version, this object is a just a reference to the base Express router, unlike in Express 3, where an app had to explicitly load it.

<h3id="req.body">req.body</h3>

<h3id="req.body">req.body</h3>

The`req.body` property returns`undefined` when the body has not been parsed. In Express 4, it returns`{}` by default.

<h3id="req.host">req.host</h3>

In Express 4, the`req.host` function incorrectly stripped off the port number if it was present. In Express 5, the port number is maintained.

<h3id="req.params">req.params</h3>

Parameters specified as wildcards are represented as arrays of segments:

app.get('/*splat', (req,res)=> {

console.dir(req.params)

})

Optional parameters that are not matched do not have a key in`req.params`. In 4.x an unmatched wildcard would be an empty string and a`:` parameter made optional by`?` had a key with value`undefined`.

The object has null prototype.

<h3id="req.query">req.query</h3>

The`req.query` property is no longer a writable property and is instead a getter. The default query parser has been changed from "extended" to "simple".