That was an interesting thread. Base on those numbers, double and single quote really does not have much speed difference and the difference is not consistent. bass_warrior's testing was meaningless, he made up cases to drive a pre-determined conclusion.

I slightly modified the first set of benchmark provided by Anonymous Monk, and when the string is a little bit longer, the chance of winning between double and single quote becomes really close to 50-50:

use warnings;

use Benchmark("cmpthese");

cmpthese(-1, {
   "double", q !eval q {$a = "this is a string" x 10}!,
   'single', q !eval q {$b = 'this is a string' x 10}!,
});

[download]

Conclusion: the difference between single and double quote are more functional than performance.

Update: when I tried x 100, double seems to win more. In a way, it shows that length of the string matters here. The overall conclusion stays, the speed difference does not mean much.

In reply to Re^2: Differences between " " and ' '? by pg
in thread Differences between " " and ' '? by Ace128

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