#micro-optimization

How to: Should I use Java's String.format() if performance is important?

Should I use Java’s String.format() if performance is important?

We have to build Strings all the time for log output and so on. Over the JDK versions we have learned when to use StringBuffer (many appends, thread safe) and StringBuilder (many appends, non-thread-safe).

What’s the advice on using String.format()? Is it efficient, or are we forced to stick with concatenation for one-liners where…

Micro-Optimizing in PHP. This article will answer what micro-optimizations are and will take a look at whether they are worth it.

Echo can be used to output concatenated variables in an interesting way.  Unlike Print, you can concatenate strings with a comma instead of a period.  But is it really all that much better than the old fashioned concatenation with a period, or embedding your variables within double-quotes?

For this test, I'm using the loopTest.php gist with the following parameters:

$testString = generateRandomString(500); // example: loopTime(0.5 /* seconds to run per function */,     function(){         global $testString;         echo 'test ', $testString;     },     function(){         global $testString;         echo 'test ' . $testString;     },     function(){         global $testString;         echo 'test ';         echo $testString;     },     function(){         global $testString;         echo "test $testString";     } );

The results are in:

Results (larger is better):   1)    389,648 iterations in 0.50 seconds.   2)    365,994 iterations in 0.50 seconds.   3)    383,308 iterations in 0.50 seconds.   4)    351,916 iterations in 0.50 seconds.

TL;DR:

Echo with a comma or two echo calls are equally fast

Using a period to concatenate strings for echo is the slow.