# Fixnum/String randomly changing type

**URL:** <https://www.ruby-forum.com/t/fixnum-string-randomly-changing-type/70102>\
**Category:** Ruby\
**Created:** [September 26, 2006, 8:49pm UTC](https://www.ruby-forum.com/t/fixnum-string-randomly-changing-type/70102 "2006-09-26T20:49:15Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![sweb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/90db22/32.png) [@sweb](https://www.ruby-forum.com/u/sweb)\
**Post date:** [September 26, 2006, 8:49pm UTC](https://www.ruby-forum.com/t/fixnum-string-randomly-changing-type/70102/1 "2006-09-26T20:49:15Z")

</div>

Hi,

I am seeing some odd behavior that look to me to like it could be a bug  
in Ruby. Being new to the language, however, I wanted to see if there  
was another explanation. I am using Ruby 1.8.4 on an Intel Mac. The  
code at the bottom of this message is an excerpt from a class in a  
larger script. It is using DBI to pull 10 fields from a MySQL database.  
The first 9 are integers (tinyint(4) in the database) and the last is a  
string (varchar(255) in the database). When I run the below program as  
is, the puts outputs:

Info[0] class: String  
Info[0] value: 0  
Info[0] class: String  
Info[0] value: 0  
.  
.  
.

However, if I uncomment the ‘info.each’ line, I get:

Info[0] class: Fixnum  
Info[0] value: 0  
0  
Info[0] class: Fixnum  
Info[0] value: 0  
0  
.  
.  
.

So, it seams that just printing out the value in an ‘each’ loop causes  
it to change from a String to a Fixnum throughout the code segment. The  
break statement makes no difference (it just reduces the output for the  
purpose of posting here). It is my understanding that the MySQL driver  
for DBI should coerce the objects to numbers since that is their type in  
the database. However, regardless of what type they start as, I don’t  
understand how adding an each loop with a print in it can change the  
type. Also, I can’t seem to reproduce this behavior in a small test  
program. I do know that the database queries are successful and are  
returning the proper values. Does anyone have any ideas? Is this a bug  
or is there some subtlety of type inferencing that I am missing?

@sthVulnID.fetch do |id|  
ids.push(id[0])  
begin  
@sthVulnInfo.execute(id[0])  
rescue DBI::DatabaseError =\> e  
puts “An error occurred getting vulnerability info”  
puts “Variables: name:”#{name}" k:"#{k}" v:"#{v}""  
puts “Error code: #{e.err}”  
puts “Error message: #{e.errstr}”  
exit  
end  
info = @sthVulnInfo.fetch\_array

```
  puts "Info is: #{info[0].class}"

```

# info.each { |newval| puts “#{newval.class}”; break }

```
  newVuln.addInfo('osvdb-location', 'physical') if ( info[0] == 1 )
  newVuln.addInfo('osvdb-location', 'local') if ( info[1] == 1 )
  newVuln.addInfo('osvdb-location', 'remote') if ( info[2] == 1 )
  newVuln.addInfo('osvdb-location', 'dialup') if ( info[3] == 1 )
  newVuln.addInfo('osvdb-location', 'unknown') if ( info[4] == 1 )
  newVuln.addInfo('osvdb-impact', 'confidentiality') if ( info[5] == 

```

1 )  
newVuln.addInfo(‘osvdb-impact’, ‘integrity’) if ( info[6] == 1 )  
newVuln.addInfo(‘osvdb-impact’, ‘availability’) if ( info[7] == 1  
)  
newVuln.addInfo(‘osvdb-impact’, ‘unknown’) if ( info[8] == 1 )  
newVuln.addInfo(‘osvdb-title’, info[9])  
end

---

<div class="post-metadata">

**Author:** ![sweb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/90db22/32.png) [@sweb](https://www.ruby-forum.com/u/sweb)\
**Post date:** [September 26, 2006, 9:09pm UTC](https://www.ruby-forum.com/t/fixnum-string-randomly-changing-type/70102/2 "2006-09-26T21:09:14Z")

</div>

> ```
> puts "Info is: #{info[0].class}"
> 
> ```
> 
> # info.each { |newval| puts “#{newval.class}”; break }

One small correction… to match the output I gave, the commented out  
line should read:

# info.each { |newval| puts “#{newval}”; break }

The behavior is the same in both cases, going from String to Fixnum when  
the ‘each’ loop is uncommented.

---

<div class="post-metadata">

**Author:** ![sweb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/90db22/32.png) [@sweb](https://www.ruby-forum.com/u/sweb)\
**Post date:** [September 26, 2006, 9:45pm UTC](https://www.ruby-forum.com/t/fixnum-string-randomly-changing-type/70102/3 "2006-09-26T21:45:58Z")

</div>

Sam W. wrote:

> Info[0] class: String  
> Info[0] value: 0  
> Info[0] class: String  
> Info[0] value: 0

And the below program is …?

---

<div class="post-metadata">

**Author:** ![sweb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/90db22/32.png) [@sweb](https://www.ruby-forum.com/u/sweb)\
**Post date:** [September 26, 2006, 9:49pm UTC](https://www.ruby-forum.com/t/fixnum-string-randomly-changing-type/70102/4 "2006-09-26T21:49:30Z")

</div>

Paul L. wrote:

> Sam W. wrote:
> 
> > Info[0] class: String  
> > Info[0] value: 0  
> > Info[0] class: String  
> > Info[0] value: 0
> 
> And the below program is …?

The program (or program fragment actually) at the bottom of my first  
message. Here it is again:

@sthVulnID.fetch do |id|  
ids.push(id[0])  
begin  
@sthVulnInfo.execute(id[0])  
rescue DBI::DatabaseError =\> e  
puts “An error occurred getting vulnerability info”  
puts “Variables: name:”#{name}" k:"#{k}" v:"#{v}""  
puts “Error code: #{e.err}”  
puts “Error message: #{e.errstr}”  
exit  
end  
info = @sthVulnInfo.fetch\_array

```
  puts "Info is: #{info[0].class}"

```

# info.each { |newval| puts “#{newval}”; break }

```
  newVuln.addInfo('osvdb-location', 'physical') if ( info[0] == 1 )
  newVuln.addInfo('osvdb-location', 'local') if ( info[1] == 1 )
  newVuln.addInfo('osvdb-location', 'remote') if ( info[2] == 1 )
  newVuln.addInfo('osvdb-location', 'dialup') if ( info[3] == 1 )
  newVuln.addInfo('osvdb-location', 'unknown') if ( info[4] == 1 )
  newVuln.addInfo('osvdb-impact', 'confidentiality') if ( info[5] ==

```

1 )  
newVuln.addInfo(‘osvdb-impact’, ‘integrity’) if ( info[6] == 1 )  
newVuln.addInfo(‘osvdb-impact’, ‘availability’) if ( info[7] == 1  
)  
newVuln.addInfo(‘osvdb-impact’, ‘unknown’) if ( info[8] == 1 )  
newVuln.addInfo(‘osvdb-title’, info[9])  
end

---

<div class="post-metadata">

**Author:** ![sweb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/90db22/32.png) [@sweb](https://www.ruby-forum.com/u/sweb)\
**Post date:** [September 26, 2006, 9:53pm UTC](https://www.ruby-forum.com/t/fixnum-string-randomly-changing-type/70102/5 "2006-09-26T21:53:59Z")

</div>

On 9/26/06, Sam W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> the ‘each’ loop is uncommented.  
> This is a documented bug. The fix for those crashes made it into  
> 1.8.5. I recommend you upgrade.

Searching ruby-core will probably give you more results. (don’t have a  
reference # handy right now).

(However, I also seem to still get crashes when doing rdoc processing.  
I haven’t been able to pin it down for a report yet though.)

Brian.

---

<div class="post-metadata">

**Author:** ![sweb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/90db22/32.png) [@sweb](https://www.ruby-forum.com/u/sweb)\
**Post date:** [October 2, 2006, 8:34pm UTC](https://www.ruby-forum.com/t/fixnum-string-randomly-changing-type/70102/6 "2006-10-02T20:34:28Z")

</div>

Brian M. wrote:

> On 9/26/06, Sam W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:
> 
> > the ‘each’ loop is uncommented.  
> > This is a documented bug. The fix for those crashes made it into  
> > 1.8.5. I recommend you upgrade.
> 
> Searching ruby-core will probably give you more results. (don’t have a  
> reference # handy right now).
> 
> (However, I also seem to still get crashes when doing rdoc processing.  
> I haven’t been able to pin it down for a report yet though.)
> 
> Brian.

Thanks Brian. Upgrading to 1.8.5 appears to have fixed the problem.

---

<div class="post-metadata">

**Author:** ![sweb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/90db22/32.png) [@sweb](https://www.ruby-forum.com/u/sweb)\
**Post date:** [September 26, 2006, 9:51pm UTC](https://www.ruby-forum.com/t/fixnum-string-randomly-changing-type/70102/7 "2006-09-26T21:51:58Z")

</div>

On 9/26/06, Sam W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> I am seeing some odd behavior that look to me to like it could be a bug  
> in Ruby. Being new to the language, however, I wanted to see if there  
> was another explanation. I am using Ruby 1.8.4 on an Intel Mac. The  
> code at the bottom of this message is an excerpt from a class in a  
> larger script. It is using DBI to pull 10 fields from a MySQL database.  
> The first 9 are integers (tinyint(4) in the database) and the last is a  
> string (varchar(255) in the database). When I run the below program as  
> is, the puts outputs:

My guess, based on what you’re seeing, is that something special is  
being done on the #each by either DBI or the DBD driver for MySQL. It  
sees that it’s really a Fixnum value that it’s supposed to be  
returning, and converts it for you.

-austin