http://www.perlmonks.org?node_id=427566


in reply to Re^3: To Single Quote or to Double Quote: a benchmark
in thread To Single Quote or to Double Quote

You see a consistent win for single quotes,
Actually, I don't. In 2 out of the 5 benchmarks, I see "double no $" beat "single no $".

The fact that "double" is slower than "single" comes partially because "single" is one character shorter than "double" (if I add a single space to "single", it takes about 3% longer), and for the rest because processing a backslash in a double quoted string means checking more cases than in a single quoted string.