# section\_4

- [Testing](/v-by-example/de/examples/section_4/testing.md)
- [Array Functions](/v-by-example/de/examples/section_4/array-functions.md)
- [JSON](/v-by-example/de/examples/section_4/json.md)
- [Files](/v-by-example/de/examples/section_4/files.md)