What are context values in Go?

Can you explain what context values are in Go?

Sure! In Go, context values are used to carry deadlines, cancellation signals, and other request-scoped values across API boundaries.

How do I create a context with values?

You can create a context with values using context.WithValue(parent Context, key, val interface{}). This returns a new context that carries the value.

Can you give me an example of using context values?

Absolutely! Here's a simple example:

ctx := context.Background()
ctx = context.WithValue(ctx, "userID", 123)
userID := ctx.Value("userID").(int)
fmt.Println(userID) // Output: 123

Are there any best practices for using context values?

Yes, it's best to use context values for request-scoped data only and avoid using them for passing optional parameters.