##not tested

if ($a){$html .= <<END;
  
  #here case A  

END
}
else{$html .= <<END;
  
  #here case B or default  

END


}
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"You cannot insert a conditional statemenent in an such a construction."

I beg to differ!

use strict;
use warnings;

print <<"END" for 1..100;
@{[$_%3?():"Fizz",$_%5?():"Buzz",$_%5&&$_%3?$_:()]}
END
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For simpler examples, it's even possible to make it sort of legible!

use strict;
use warnings;

print <<"END" for 1..100;
@{[  ($_ % 2) ? 'Odd' : 'Even'  ]}
END
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toby döt ink

ehehe i had some precognition when i wrote that..
Better i would say: 'I tried but it was a...' but in Perl many many things are possible!

Thanks tobyink

There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

thanks for your reply and pointer to the doc.
I just do not want to write the same code again and again, can I write a function and pass 'onload' or 'onChange' in a variable? so that it would resolve the $func value as -onChange or -onload ?

You could make life much easier for yourself by using a templating system rather than creating HTML in this manner, but you already know that.

Yes, we can. Like that (untested):

...
my $trigger = 'onload';

                 $html .= <<END;
...
                   <td bgcolor="#EEEEEE">@{[ $qry->popup_menu(-id=>'ID
+', -name=>'PS', -size=>10, -values=>$array_ref, -labels=>$hash_ref,  
+-${trigger}=>"fetchData(id,'','','')") ]}</td>
   
                   </tr>
                </table>

END
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The original code did already interpolate a list expression in the heredoc string (@{[ ... ]} was already present). So you just have to replace the fixed text part (onChange) in the above expression (...) with a string variable (here I used $trigger).

G'day ghosh123,

"In the above code, what does this <<END and END mean ?"

The construct

<<END;
...
END
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is called a heredoc.

Simplistically, it's just a string. In perlop, it's introduced in "Quote and Quote-like Operators" with a lot more detail in "Quote-Like Operators".

"how can I change the code which is in between that <<END and END, to insert a if-else condition for that popup_menu."

Now that you know that's a string, you probably won't be trying to do that any more. :-)

I'd suggest something along these lines:

my $popup_string;

if (some_condition()) {
    $popup_string = ...;
}
else {
    $popup_string = ...;
}

$html .= <<END;
...
<td bgcolor="#EEEEEE">$popup_string</td>
...
END
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wxPPIxregexplain.pl

ppi_dumper -W -C foo.pl
...
  PPI::Statement
    PPI::Token::Symbol  	'$html'
    PPI::Token::Operator  	'.='
    PPI::Token::HereDoc  	'<<END'
    PPI::Token::Structure  	';'
...

Now that you know the name (heredoc), you can search for it,  [perldoc://heredoc] heredoc -> perlop#<<EOF