go What is the difference between = and

go What is the difference between = and <- in golang

When this verb is present, the error returned by fmt.Errorf will have an Unwrap method returning the argument of %w, which must be an error. In all other ways, %w is identical to %v. And finally, if your error type supports the %+v verb variant, then you will, of course, need to use that, if you desire the detailed output.

I’ve highlighted the parts relevant to your question.
You are thinking it’s related to assignment as in other languages.
When this verb is present, the error returned by fmt.Errorf will have an Unwrap method returning the argument of %w, which must be an error.
Please note the links to the Go specification which speak at greater length to the operators.

Use %w instead of %v or %s:

In your code, a value “j” is being sent to the channel “jobs”.
But, In Go 1.13, the fmt.Errorf function supports a new %w verb.
%s %v and %w can be used to format errors in Go (turn them into strings with fmt.Errorf).
In the other 0.001% of cases, %v and %s probably “should” behave the same, except when the error value is nil, but there are no guarantees.
The details for how %s and %v are implemented are available in the docs.

So in practice, this means that %s and %v are identical, except when a Format() method exists on the error type (or when the error is nil). In the other 0.001% of cases, %v and %s probably “should” behave the same, except when the error value is nil, but there are no guarantees. The friendlier output of %v for nil errors may be reason to prefer %v (see below). %s %v and %w can be used to format errors in Go (turn them into strings with fmt.Errorf). But, In Go 1.13, the fmt.Errorf function supports a new %w verb.

Your Answer

Please note the links to the Go specification which speak at greater length to the operators.

Okay, so what about %v and %s?

The details for how %s and %v are implemented are available in the docs. I’ve highlighted the parts relevant to your question. You are thinking it’s related to assignment as in other languages. In your golang curl code, a value “j” is being sent to the channel “jobs”. You cannot use the operators interchangeably because of a type mismatch.