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For 2023 - we are now fully retired from IT training.
We have made many, many friends over 25 years of teaching about Python, Tcl, Perl, PHP, Lua, Java, C and C++ - and MySQL, Linux and Solaris/SunOS too. Our training notes are now very much out of date, but due to upward compatability most of our examples remain operational and even relevant ad you are welcome to make us if them "as seen" and at your own risk.

Lisa and I (Graham) now live in what was our training centre in Melksham - happy to meet with former delegates here - but do check ahead before coming round. We are far from inactive - rather, enjoying the times that we are retired but still healthy enough in mind and body to be active!

I am also active in many other area and still look after a lot of web sites - you can find an index ((here))

Posted by admin (Graham Ellis), 22 December 2002
Perl uses the concept of "context" to work out what to do with a list - if you write @stuff in your code, it depends whether it's somewhere that a list actually makes sense (in which case the list is used), somewhere where a list does not make sense (in which case Perl uses the length of the list), or in double quotes (in which case Perl concatenates all elements of the list with a copy of the variable $" - default a space character - between each).

Here's a sample piece of code that I wrote during the Perl course I was running last week - I think I had the opportunity to add a few comments for once!

@stuff = (10,"twenty",30,"forty");

@morestuff = @stuff;   # take copy of list
$stuffabout = @stuff;   # you must mean the LENGTH of the list!

print @stuff,"\n";
print @morestuff,"\n";
print $#morestuff,"\n";         # 3 (0 to 3)
print $stuffabout,"\n";         # 4 (there are 4 elements)

($first,$second,$third,$next) = @stuff;
print "$next $second $first $third\n";

($oneth, @rest) = @stuff;       # 10 into $oneth, rest into @rest
print @rest,"\n";               # No spaces
print "@rest\n";                # Space between each
print @rest+0,"\n";             # Scalar - print the length

($stuffab) = @stuff;    # force list context.  1st element!
print $stuffab,"\n";

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