Test: foreach writing ref vs. key

No Description

Historical Results

Based on (1) saved test runs, The test labeled "non-referenced" was (on average) the faster by 0.0037 seconds, (0.738% faster)

non-referenced 100%

referenced 99.262%

The non-referenced test took 0.5021 seconds.
The referenced test took 0.5059 seconds.

Nitty-Gritty

Each test case ran 20 random code order iterations consisting of 141,951 loops for a total of 2,839,020 runs.

Line execution difference (0.000001) milliseconds.
Avg difference (0.000) milliseconds per 141,951 loops.
Total difference 3.74 milliseconds for 2,839,020 loops

The iteration variablity for Code 1 was (0.0000) milliseconds and Code 2 was (0.0000) milliseconds. The lower and the closer together there values are the more accurate the results are.

Code

The first test, "non-referenced", was:

foreach ($GLOBALS['dummy'] as $k => $v)
	$GLOBALS['dummy'][$k][1]++;
unset($v);

The second test, "referenced", was:

foreach ($GLOBALS['dummy'] as $k => &$v)
	$v[1]++;
unset($v);

PHP Benchmarks