We currently maintain sample code in C#, Python, and Java in a GitHub repo. Please note that while the client libraries are available, they are deprecated and preserved for archival purposes.
These samples all assume that you have a working developer's account, and you've already set up a project in the Developers Console that includes the Surveys API and credentials for use with OAuth 2.0.
If you still need to set up your project, you can find a complete description of how to set up the Developers Console in the quick start guide.
Sample Survey Data
You may access any of the publicly available example surveys via the API to test your code.