Using quote-like-operators or quotes in the perl's printf

Question

Reading perl sources I saw many times the next construction:

printf qq[%s\n], getsomestring( $_ );

But usually it is written as

printf "%s\n", getsomestring( $_ );

The question:

• is here any "good practice" what is the correct way, and if yes
• when is recommended to use the longer qq[...] vs the "..."
• or it is only pure TIMTOWTDI?

The perlop doesn't mention anything about this.

Answer 1

You can use qq() as an alternative double quote method, such as when you have double quotes in the string. For example:

"\"foo bar\""

Looks better when written

qq("foo bar")

When in the windows cmd shell, which uses double quotes, I often use qq() when I need interpolation. For example:

perl -lwe "print qq($foo\n)"

The qq() operator -- like many other perl operators such as s///, qx() -- is also handy as you demonstrate because it can use just about any character as its delimiter:

qq[this works]
qq|as does this|
qq#or this#

This is handy for when you have many different delimiters in the string. For example:

qq!This is (not) "hard" to quote!

As for best practice, I would say use whatever is more readable.

Answer 2

I always use qq[...] when there are quotes in the strings, example:

qq["here you are", he said]

If not, for me is more readable the use of ""