I have no problem with block scope, but when combined with a syntax that is
create var if not already created when using multiple vars and some are already
created. I am sure it is a cause of many hard to track bugs, especially in
larger methods. The whole thing is brought about by the error handling in go...
but that’s another topic. :)
Sent from my iPhone
> On Sep 4, 2018, at 10:45 AM, Michael Jones <michael.jo...@gmail.com> wrote:
>
> Block scope is a superpower since Algol.
>
>> On Tue, Sep 4, 2018 at 7:29 AM Robert Engels <reng...@ix.netcom.com> wrote:
>> The real gotcha is this though,
>>
>> var x int
>> if blah {
>> x,err := somefunc()
>> }
>>
>> Probably does not do what you think as the value from somefunc() will not be
>> available outside of the if statement...
>>
>> This is a poor design choice by golang IMO but it is what it is...
>>
>>> On Sep 4, 2018, at 9:22 AM, Nate Finch <nate.fi...@gmail.com> wrote:
>>>
>>> Others covered this, but let me try to explain. In Go, plain = just
>>> assigns to an already existing variable
>>>
>>> var x bool // declares a variable, it starts with the zero value for the
>>> type
>>> x = true // assigns a value to the variable
>>> y := true // declares the variable and assigns it a value
>>>
>>> Now, the tricky thing is when you have two values being assigned/declared,
>>> like foo, err := bar(). In this case, as long as either or both variables
>>> hasn't been declared, then := will declare one or both, and assign to one
>>> that's already declared. This makes it easier to do long lists of calls
>>> that return an error, without having to use err1, err2, etc. But it does
>>> kind of muddy the waters for when to use = and when to use :=.
>>>
>>> := has to always make at least one new variable. = always just copies a
>>> value to an existing variable or struct field. So, like, you can't ever
>>> use := to put something in a struct field (s.foo := bar will never work).
>>>
>>> You'll get the hang of it. You'll use := most of the time, and only = for
>>> spots where the stuff on the left hand side is already declared.
>>> --
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>>
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>
>
> --
> Michael T. Jones
> michael.jo...@gmail.com
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