String Outputecho vs. print
Is a there a difference between what option you use to output your content?. Called within Output Buffering 1'000x
+ 191 %
echo 'aaaaaaaaaaaaaaaaaaaaaaaaaaaa'
Total time: 200 µsview code
+ 184 %
print 'aaaaaaaaaaaaaaaaaaaaaaaaaaaa'
Total time: 193 µsview code
+ 607 %
echo 'aaaaaaa'.'aaaaaaa'.'aaaaaaa'.'aaaaaaa'
Total time: 637 µsview code
+ 531 %
echo 'aaaaaaa','aaaaaaa','aaaaaaa','aaaaaaa'
Total time: 557 µsview code
+ 642 %
print 'aaaaaaa'.'aaaaaaa'.'aaaaaaa'.'aaaaaaa'
Total time: 673 µsview code
+ 782 %
$a = 'aaaaaaa';
echo 'aaaaaaa'.$a.'aaaaaaa'.$a
Total time: 820 µsview code
+ 704 %
$a = 'aaaaaaa';
echo 'aaaaaaa',$a,'aaaaaaa',$a
Total time: 738 µsview code
+ 795 %
$a = 'aaaaaaa';
print 'aaaaaaa'.$a.'aaaaaaa'.$a
Total time: 834 µsview code
+ 770 %
$a = 'aaaaaaa';
echo $a.$a.$a.$a
Total time: 808 µsview code
+ 720 %
$a = 'aaaaaaa';
echo $a,$a,$a,$a
Total time: 755 µsview code
+ 774 %
$a = 'aaaaaaa';
print $a,$a,$a,$a
Total time: 812 µsview code
Conclusion:
In reality the echo and print functions serve the exact purpose and therefore in the backend the exact same code applies. The one small thing to notice is that when using a comma to separate items whilst using the echo function, items run slightly faster.
Variable Type CheckingisSet() vs. empty() vs. is_array()
What is the performance of isSet() and empty(). Call 2'000x
+ 103 %
isSet() with var that was set
Total time: 203 µsview code
+ 104 %
empty() with var that was set
Total time: 203 µsview code
+ 100 %
isSet() with var that was *not* set
Total time: 196 µsview code
+ 100 %
empty() with var that was *not* set
Total time: 197 µsview code
+ 112 %
isSet() with array-var that was set
Total time: 219 µsview code
+ 103 %
empty() with array-var that was set
Total time: 203 µsview code
+ 104 %
isSet() with array-var that was *not* set
Total time: 204 µsview code
+ 100 %
empty() with array-var that was *not* set
Total time: 197 µsview code
+ 504 %
is_array() of an array
Total time: 989 µsview code
+ 506 %
is_array() of a string
Total time: 992 µsview code
+ 1056 %
is_array() of a non set value
Total time: 2072 µsview code
+ 1077 %
isSet() AND is_array() of a non set value
Total time: 2114 µsview code
Conclusion:
isSet() and empty() are identical. So alway check if val is set at all befor using type-checking. E.g. if (isSet($foo) AND is_array($foo))
Quote Typesdouble (") vs. single (') quotes
Is a there a difference in using double (") and single (') quotes for strings. Call 1'000x
+ 222 %
single (') quotes. Just an empty string: $tmp[] = '';
Total time: 709 µsview code
+ 100 %
double (") quotes. Just an empty string: $tmp[] = "";
Total time: 320 µsview code
+ 164 %
single (') quotes. 20 bytes Text : $tmp[] = 'aaaaaaaaaaaaaaaaaaaa';
Total time: 525 µsview code
+ 119 %
double (") quotes. 20 bytes Text : $tmp[] = "aaaaaaaaaaaaaaaaaaaa";
Total time: 381 µsview code
+ 121 %
single (') quotes. 20 bytes Text and 3x a $ : $tmp[] = 'aa $ aaaa $ aaaa $ a';
Total time: 387 µsview code
+ 117 %
double (") quotes. 20 bytes Text and 3x a $ : $tmp[] = "aa $ aaaa $ aaaa $ a";
Total time: 375 µsview code
+ 121 %
double (") quotes. 20 bytes Text and 3x a \$ : $tmp[] = "aa \$ aaaa \$ aaaa \$ a";
Total time: 388 µsview code
Conclusion:
In today's versions of PHP it looks like this argument has been satisfied on both sides of the line. Lets all join together in harmony in this one!
Using the &-ref-operator...as a so called "alias"
Is a good idea to use the &-ref-operator to substitute (or alias) a complex mutidim-array? . Call 1'000x
E.g. $person = &$aHach["country"]["zip"]["street"]["number"]["name"]
+ 174 %
$alias = $aSingleDimArray[$i]
Total time: 658 µsview code
+ 100 %
$alias = &$aSingleDimArray[$i]
Total time: 378 µsview code
+ 213 %
$alias = $aMultiDimArray[$i]["aaaaa"]["aaaaaaaaaa"]
Total time: 804 µsview code
+ 658 %
$alias = &$aMultiDimArray[$i]["aaaaa"]["aaaaaaaaaa"]
Total time: 2487 µsview code
+ 260 %
$alias = veryMultiDimArray[$i]["a"]["aa"]["aaa"]["aaaa"]["aaaaa"]
Total time: 983 µsview code
+ 1353 %
$alias = &$veryMultiDimArray[$i]["a"]["aa"]["aaa"]["aaaa"]["aaaaa"]
Total time: 5114 µsview code
Conclusion:
Whilst only using a one dimensional array, it's actually faster to use an alias, but anything larger will result in a performance drop.
Counting LoopsFor vs. While
Is there an actual difference between counting up between the for loop and the while loop?
+ 114 %
for($i = 0; $i < 1000000; ++$i);
Total time: 79654 µsview code
+ 100 %
$i = 0; while($i < 1000000) ++$i;
Total time: 69575 µsview code
Conclusion:
Well there you have it, the while loop 90% of the time is indeed slightly faster
Using the =&-ref-operator$obj = $someClass->f() vs. $obj =& $someClass->f()
Is a good idea to use the =&-ref-operator when calling a function in an object? Call 1'000x
+ 100 %
$obj = $someClass->f();
Total time: 681 µsview code
+ 207 %
$obj =& $someClass->f();
Total time: 1411 µsview code
Conclusion:
Unless your extremely worried about how much RAM your using, leaving the &-ref-operator out seems like the slightly faster option.
Read Loop:foreach() vs. for() vs. while(list() = each())
What is the best way to loop a hash array?
Given is a Hash array with 100 elements, 24byte key and 10k data per entry
+ 100 %
foreach($aHash as $val);
Total time: 15 µsview code
+ 965 %
while(list(,$val) = each($aHash));
Total time: 145 µsview code
+ 148 %
foreach($aHash as $key => $val);
Total time: 22 µsview code
+ 1059 %
while(list($key,$val) = each($aHash));
Total time: 159 µsview code
+ 340 %
foreach($aHash as $key=>$val) $tmp[] = $aHash[$key];
Total time: 51 µsview code
+ 1132 %
while(list($key) = each($aHash)) $tmp[] = $aHash[$key];
Total time: 170 µsview code
+ 433 %
Get key-/ value-array: foreach($aHash as $key[]=>$val[]);
Total time: 65 µsview code
+ 360 %
Get key-/ value-array: array_keys() / array_values()
Total time: 54 µsview code
+ 506 %
$key = array_keys($aHash);
$size = sizeOf($key);
for ($i=0; $i<$size; $i++) $tmp[] = $aHash[$key[$i]];
Total time: 76 µsview code
Conclusion:
In all cases I've found that the foreach loop is substantially faster than both the while() and for() loop procedures. One thing to note is that when using an entire loop from the start it's extremely good to use the reset() function in all examples
Given that the previous version of the tests have been very controvercial and incorrect, I must appologise for forgetting to implement the reset() function to allow the while() loops to start from the beginning instead of the end. Thanks to Anthony Bush for spotting this out.
Control Structuresswitch/case/default vs. if/elseif/else
Is a there a difference between switch and if structures?. Call 1'000x
+ 134 %
if and elseif (using ==)
Total time: 215 µsview code
+ 117 %
if, elseif and else (using ==)
Total time: 188 µsview code
+ 100 %
if and elseif (using ===)
Total time: 161 µsview code
+ 100 %
if, elseif and else (using ===)
Total time: 161 µsview code
+ 132 %
switch / case
Total time: 212 µsview code
+ 147 %
switch / case / default
Total time: 237 µsview code
Conclusion:
Using a switch/case or if/elseif is almost the same. Note that the test is unsing === (is exactly equal to) and is slightly faster then using == (is equal to).
Counting LoopsFor-loop test
Is it worth the effort to calculate the length of the loop in advance?
e.g. "for ($i=0; $i<$size; $i++)" instead of "for ($i=0; $i<sizeOf($x); $i++)"
A loop with 1000 keys with 1 byte values are given.
+ 117 %
With pre calc - count()
Total time: 243 µsview code
+ 52250 %
Without pre calc - count()
Total time: 108130 µsview code
+ 100 %
With pre calc - sizeof()
Total time: 207 µsview code
+ 49268 %
Without pre calc - sizeof()
Total time: 101959 µsview code
Conclusion:
Unsurprising results... this is one of the easiest things to implement in any application and is the widest agreed upon benchmarking item within the online PHP community. The results basically speak for themselves.
Modify Loop:
foreach() vs. for vs. while(list() = each())
What would happen if we alter the reading loop test to test the results of a loop created to simply alter the data in each of the values in the array?
Given again is a Hash array with 100 elements, 24byte key and 10k data per entry.
+ 438 %
foreach($aHash as $key=>$val) $aHash[$key] .= "a";
Total time: 324 µsview code
+ 225 %
while(list($key) = each($aHash)) $aHash[$key] .= "a";
Total time: 166 µsview code
+ 100 %
$key = array_keys($aHash);
$size = sizeOf($key);
for ($i=0; $i<$size; $i++) $aHash[$key[$i]] .= "a";
Total time: 74 µsview code
Conclusion:
Proof in this example shows how functionally murderous the foreach() loop can be.