# Use of case statement doesn't work as I expected, what am I doing wrong?

**URL:** <https://www.ruby-forum.com/t/use-of-case-statement-doesnt-work-as-i-expected-what-am-i-doing-wrong/118954>\
**Category:** Ruby\
**Created:** [November 1, 2007, 6:00pm UTC](https://www.ruby-forum.com/t/use-of-case-statement-doesnt-work-as-i-expected-what-am-i-doing-wrong/118954 "2007-11-01T18:00:30Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![mobileamusement](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/59ef9b/32.png) [@mobileamusement](https://www.ruby-forum.com/u/mobileamusement)\
**Post date:** [November 1, 2007, 6:00pm UTC](https://www.ruby-forum.com/t/use-of-case-statement-doesnt-work-as-i-expected-what-am-i-doing-wrong/118954/1 "2007-11-01T18:00:30Z")

</div>

Hi all,

I have an object ( a website tester) that can return various values.  
One of which is Net:HTTPOK, I want to use a case statement to evaluate  
this and set a variable called ‘severity’, as follows:

result = TestWebsite::test( site )  
case result  
when Net::HTTPOK  
severity = :INFO  
when SocketError  
severity = :ERROR  
else  
severity = :WARN  
end

However, when Net::HTTPOK is returned, the severity variable ALWAYS  
ends up as :WARN instead of :INFO.

Using IRB I have manually entered the code in as follows:

> > site = ‘[beautyandthebrand.co.uk](http://beautyandthebrand.co.uk)’  
> > =\> “[beautyandthebrand.co.uk](http://beautyandthebrand.co.uk)”  
> > result = TestWebsite::test( site )  
> > =\> Net::HTTPOK

Then ran the following tests:

> > result == Net::HTTPOK  
> > =\> true  
> > result != Net::HTTPOK  
> > =\> false

This to me just proves the result I am getting is Net::HTTPOK, but why  
can’t I get it to match in the case statement?

Many thanks for any help

Gabriel

---

<div class="post-metadata">

**Author:** ![mobileamusement](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/59ef9b/32.png) [@mobileamusement](https://www.ruby-forum.com/u/mobileamusement)\
**Post date:** [November 1, 2007, 6:47pm UTC](https://www.ruby-forum.com/t/use-of-case-statement-doesnt-work-as-i-expected-what-am-i-doing-wrong/118954/2 "2007-11-01T18:47:55Z")

</div>

Hi –

On Fri, 2 Nov 2007, Gabriel D. wrote:

> when SocketError  
> =\> “[beautyandthebrand.co.uk](http://beautyandthebrand.co.uk)”  
> I get it to match in the case statement?  
> The test that the case statement is running is this:

Net::HTTPOK === result # note the order, and the 3 equal signs

I don’t know exactly what Net::HTTPOK is, or how it handles ===, but  
evidentally it doesn’t consider itself “threequal” to result.

David

---

<div class="post-metadata">

**Author:** ![mobileamusement](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/59ef9b/32.png) [@mobileamusement](https://www.ruby-forum.com/u/mobileamusement)\
**Post date:** [November 1, 2007, 6:56pm UTC](https://www.ruby-forum.com/t/use-of-case-statement-doesnt-work-as-i-expected-what-am-i-doing-wrong/118954/3 "2007-11-01T18:56:07Z")

</div>

On Nov 1, 2007, at 12:36 PM, Gabriel D. wrote:

> else  
> severity = :WARN  
> end
> 
> However, when Net::HTTPOK is returned, the severity variable ALWAYS  
> ends up as :WARN instead of :INFO.

There are two issues:

1. case uses the === operator and not ==

This means that the comparisons in your case statement are:

Net::HTTPOK === result  
SocketError === result

1. Class#=== doesn’t test for equality. It checks to see if  
the argument is an instance of the class, which is not  
true in your case, Net::HTTPOK is not an instance of itself.

Just to be clear, Net::HTTPOK and SocketError are class objects  
(instances of Class) and so they use Class#=== in case statements.

You could rewrite your case as an if/then/else or use the alternate  
form of the case statement:

case  
when result == Net::HTTPOK  
severity = :INFO  
when result == SocketError  
severity = :ERROR  
else  
severity = :WARN  
end

There of course lots of other possibilities:

severity\_map = Hash.new(:WARN).merge(Net::HTTPOK =\> :INFO,  
SocketError =\> :ERROR)

severity = severity\_map[TestWebsite::test(site)]

Gary W.