Final answer:
To allow customers to update their information via a form, the POST method is typically used for its security and absence of data in the URL. Alternatives like GET, PUT, or PATCH methods may also be used, depending on the use case and requirements, such as RESTful API design or data visibility in the URL.
Step-by-step explanation:
The form submission method that should be used when allowing customers to update their information via a form depends on the context of the use case and the developer's requirements. For updates, a safe and common practice would be to use the POST method, as it allows you to send updated or new information to be stored on the server, ensuring that the data is not visible in the URL and providing a higher level of security.
However, if the update needs to be reflected in the URL, for purposes such as bookmarking or sharing, the GET method could also be considered, keeping in mind that query string parameters will be visible and therefore should not include sensitive information. The PUT or PATCH methods are also suitable options for updating resources and are commonly used in APIs adhering to RESTful practices.
Ultimately, the method chosen should be in line with the developer's requirements, considering factors such as security, data size, idempotency, and whether it is a web form or an API call. Proper encoding and validation of the form data should always be implemented regardless of the method chosen to prevent security issues such as CSRF (Cross-Site Request Forgery) or SQL injection attacks.