Performance of variable expansion vs. sprintf in PHP

Question

Regarding performance, is there any difference between doing:

$message = \"The request $request has $n errors\";

and

$messa         


        

Answer 1

I am surprised, but for PHP 7.* "$variables replacement" is the fastest approach:

$message = "The request {$request} has {$n} errors";

You can simply prove it yourself:

$request = "XYZ";
$n = "0";
$mtime = microtime(true);
for ($i = 0; $i < 1000000; $i++) {
        $message = "The request {$request} has {$n} errors";
}
$ctime = microtime(true);
echo '

"variable $replacement timing": '.  ($ctime-$mtime);




$request = "XYZ";
$n = "0";
$mtime = microtime(true);
for ($i = 0; $i < 1000000; $i++) {
        $message = 'The request '.$request.' has '.$n.' errors';
}
$ctime = microtime(true);
echo '

"concatenation" . $timing: '.  ($ctime-$mtime);



$request = "XYZ";
$n = "0";
$mtime = microtime(true);
for ($i = 0; $i < 1000000; $i++) {
        $message = sprintf('The request %s has %d errors', $request, $n);
}
$ctime = microtime(true);
echo '

sprintf("%s", $timing): '.  ($ctime-$mtime);

The result for PHP 7.3.5:

"variable $replacement timing": 0.091434955596924

"concatenation" . $timing: 0.11175799369812

sprintf("%s", $timing): 0.17482495307922

Probably you already found recommendations like 'use sprintf instead of variables contained in double quotes, it’s about 10x faster.' What are some good PHP performance tips?

I see it was the truth but one day. Namely before the PHP 5.2.*

Here is a sample of how it was those days PHP 5.1.6:

"variable $replacement timing": 0.67681694030762

"concatenation" . $timing: 0.24738907814026

sprintf("%s", $timing): 0.61580610275269