Rails if statement results in illegal octal digit error?

Question

Hi Everyone,

I have the following if statement in my view:

<% if @kase.jobno[1,2].to_i == 10 then %>
  <img src="../images/2010.jpg" alt="2010">
<% elsif @kase.jobno[1,2].to_i == 11 then %>
  <img src="../images/2011.jpg" alt="2011">
<% else %>
  <img src="../images/document.jpg" alt="Document" />
<% end %>

It works absolutely perfectly, however, if I want to extend the range of the statement to show a particular image if the @kase.jobno field includes the number 08 and the change the statement to the following:

<% if @kase.jobno[1,2].to_i == 09 then %>
  <img src="../images/20109.jpg" alt="2009">
<% elsif @kase.jobno[1,2].to_i == 10 then %>
  <img src="../images/2010.jpg" alt="2010">
<% elsif @kase.jobno[1,2].to_i == 11 then %>
  <img src="../images/2011.jpg" alt="2011">
<% else %>
  <img src="../images/document.jpg" alt="Document" />
<% end %>

then I get the following error:

Illegal octal digit

which points to the 09 value.

Is it impossible to have an if statement which compares against an 0X (number starting with zero and followed by other digit) number?

Thanks,

Danny

Answer 1

Starting a number with 0 tells Ruby that it is an octal number. 09 is an illegal octal number since those numbers count from 0 to 7 (and not to 9). So after 07 comes 010 which is 8 in the decimal system, followed by 011 which is decimal 9.

If you want to check if the year is 2009 you could use this check:

<% if @kase.jobno[1,2].to_i == 9 then %>
  <img src="../images/2009.jpg" alt="2009">
<% end %>

(so just remove the 0 in front of 09)

Answer 2

Alternatively, just do the comparison with the string

<% if @kase.jobno[1,2] == "09" then %>
  <img src="../images/20109.jpg" alt="2009">