Re: $foo = << "END"

It throws an error, because that's an incomplete statement. What you have there is most of the first line of a heredoc, which when completed looks like this:

my $foo = << "END";
This is some text that will be placed in the scalar \$foo.
Variables like $this and $that will be interpolated.
END
print $foo;
[download]

A couple of gotchas on using heredocs: note that the opening line has a closing semicolon and the closing one does not. (I think PHP's heredoc works the other way around.) Also, the closing delimiter word must not have any whitespace on the line before it, unless you go to some trouble to quote the same whitespace as part of the opening delimiter.

Aaron B.
My Woefully Neglected Blog, where I occasionally mention Perl.

Comment on Re: $foo = << "END" Download Code

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Re^2: $foo = << "END" by akagrawal3 (Beadle) on Mar 05, 2012 at 14:01 UTC
Ya thats right but we could have directly written as `my $foo =" This is some text that will be placed in the scalar \$foo. Variables like $this and $that will be interpolated." print $foo;` [download] Does using `<< "END"` have any specific advantage?	[reply] [d/l] [select]
Re^3: $foo = << "END" by choroba (Cardinal) on Mar 05, 2012 at 14:06 UTC
You can include double quotes without escaping.	[reply]
Re^4: $foo = << "END" by aaron_baugher (Curate) on Mar 05, 2012 at 15:38 UTC
Also, sometimes they make indentation and blank lines clearer. You can include those with multi-line quoted strings, but that's not always as clear. For one thing, you can't justify the first line to the left without adding a newline at the beginning. These are equivalent, and I think the first is clearer: `my $foo = <<END; paragraph 1 line 2 paragraph 2 line 2 END my $bar = qq\| paragraph 1 line 2 paragraph 2 line 2 \|;` [download] Aaron B. My Woefully Neglected Blog, where I occasionally mention Perl.	[reply] [d/l]
Re^3: $foo = << "END" by runrig (Abbot) on Mar 05, 2012 at 16:11 UTC
Does using << "END" have any specific advantage? You can set your text editor to syntax highlight your heredoc as SQL, XML, HTML or whatever instead of plain text.	[reply]
Re^3: $foo = << "END" by aaron_baugher (Curate) on Mar 05, 2012 at 23:08 UTC
Except that your example is not the same. Yours has a leading space that mine doesn't have, and mine has a trailing newline that yours doesn't. Those are things that can be more easily spotted with a heredoc. On the other hand, some things can be tricky to do with a heredoc, like ending a multi-line string without a newline. So each method has its own best uses. Aaron B. My Woefully Neglected Blog, where I occasionally mention Perl.	[reply]