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Go maps

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David Eisinger
2023-07-16 00:22:49 -04:00
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@@ -116,7 +116,17 @@ I find [Go][1] really compelling, even though it's not super applicable to my jo
> Usually, a struct is used to create a custom error type. By convention, custom error type names should end with `Error`. Also, it is best to set up the `Error() string` method with a pointer receiver, see this [Stackoverflow comment](https://stackoverflow.com/a/50333850) to learn about the reasoning. Note that this means you need to return a pointer to your custom error otherwise it will not count as `error` because the non-pointer value does not provide the `Error() string` method. > Usually, a struct is used to create a custom error type. By convention, custom error type names should end with `Error`. Also, it is best to set up the `Error() string` method with a pointer receiver, see this [Stackoverflow comment](https://stackoverflow.com/a/50333850) to learn about the reasoning. Note that this means you need to return a pointer to your custom error otherwise it will not count as `error` because the non-pointer value does not provide the `Error() string` method.
* [Maps][20]
> A Go map type looks like this: `map[KeyType]ValueType`
> To initialize a map, use the built in `make` function: `m = make(map[string]int)`
> This statement retrieves the value stored under the key `"route"` and assigns it to a new variable i: `i := m["route"]`. If the requested key doesn’t exist, we get the value type’s _zero value_. In this case the value type is `int`, so the zero value is `0`.
> A two-value assignment tests for the existence of a key: `i, ok := m["route"]`
[17]: https://stackoverflow.com/a/40951013 [17]: https://stackoverflow.com/a/40951013
[18]: https://go.dev/doc/effective_go#named-results [18]: https://go.dev/doc/effective_go#named-results
[19]: https://exercism.org/tracks/go/concepts/errors [19]: https://exercism.org/tracks/go/concepts/errors
[20]: https://go.dev/blog/maps