Summary  
This chapter explains how to implement update and delete operations by handling HTTP PUT (or PATCH) and DELETE requests, extracting route parameters and request bodies to modify or remove records.

General domain of usage  
Building RESTful web APIs



In addition to creating data, APIs often need to update and delete existing records.

To update data, you can use PUT or PATCH requests.

```javascript id="2k9mxe"
app.put('/users/:id', (req, res) => {
  const id = Number(req.params.id);
  const updatedData = req.body;

  const user = users.find(u => u.id === id);

  if (user) {
    user.name = updatedData.name;
    res.json(user);
  } else {
    res.send('User not found');
  }
});
```

To delete data, you use a DELETE request:

```javascript id="7b3qsn"
app.delete('/users/:id', (req, res) => {
  const id = Number(req.params.id);

  users = users.filter(u => u.id !== id);

  res.send('User deleted');
});
```

Examples:

* `PUT '/users/1'`: updates user with id 1;
* `DELETE '/users/1'`: deletes user with id 1.

These operations allow you to modify and remove data in your application.


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Updating and Deleting Data