Variable Formating

[g0dzuki]

This is probably a fairly trivial question but it's sparked my curiousity. I've noticed two different ways people echo variables in their scripts:

1) echo "here's my $variable";

and

2) echo "here's my " . $variable . "";

Is there any benefit to using one method over the other or is it just a matter of coding preference? Is there added security with using the second?

Thanks....

~ Chris

[phpmavenman]

I do believe that a more scientific study needs to be performed but I found some interesting results from the following test script that I put together:

$world="world";
ob_start();
$startTimeA=date("U");
for($i=0;$i<300000;$i++){
	echo "hello $world<br>";
}
$endTimeA=date("U");
ob_end_clean();
ob_start();
$startTimeB=date("U");
for($j=0;$j<300000;$j++){
	echo "hello ".$world."<br>";
}
$endTimeB=date("U");
ob_end_clean();
echo "Test A = ".($endTimeA-$startTimeA)." secs<br>";
echo "Test B = ".($endTimeB-$startTimeB)." secs";

The results were as follows:
Ran 10 times and consistently the variable inside the string quotes performed slower than concatenating with period. Below 1-5 was performed as the code looks above. 6-10 was performed with the echo strings being swaped from A to B and vise versa.

Results:
1) A-7 secs, B-6 secs
2) A-7 secs, B-7 secs
3) A-7 secs, B-6 secs
4) A-7 secs, B-6 secs
5) A-7 secs, B-6 secs

6) A-6 secs, B-7 secs
7) A-6 secs, B-7 secs
8) A-6 secs, B-7 secs
9) A-6 secs, B-7 secs
10) A-6 secs, B-7 secs

Conclusion in my rough test environment (your results may vary based on server and environment. This server is a private test server with no public internet traffic influencing the results):

echo "Hello ".$world."<br>";

executes faster than

echo "Hello $world<br>";

Just my 2 cents with a little bit of data to back it up.

[Installer]

nm

[laserlight]

There's no added security either way.

The first method will be slower than the second as variable interpolation is more expensive than string concatenation.
But it probably wont be that much slower to really matter.

[LordShryku]

There's also
echo "here's my {$variable}";

It's a matter of preference, since variables will parse within double quotes. But the concatenation or brackets are neccesary if it's an array variable. It also won't parse if you're using single quotes instead of double quotes.