PHP Benchmarks

Performance comparison of PHP code alternatives.

Test: array_merge vs. + (string keys)

Semantically, array_merge() and + are identical when the arrays contain string keys.

View test history (2) Run this test again Return to test menu

Result: Saved

The test labeled "array_merge()" was the faster by 0.0043 seconds, (0.439% faster)

array_merge() 100%
add operator 99.561%

The array_merge() test took 0.9763 seconds.
The add operator test took 0.9806 seconds.


Each test case ran 20 random code order iterations consisting of 272,136 loops for a total of 5,442,720 runs.

  • Line execution difference (0.000001) milliseconds.
  • Avg difference (0.215) milliseconds per 272,136 loops.
  • Total difference 4.30 milliseconds for 5,442,720 loops

The iteration variablity for Code 1 was (0.9893) milliseconds and Code 2 was (0.8752) milliseconds. The lower and the closer together there values are the more accurate the results are.


The first test, "array_merge()", was:

$array = array_merge($GLOBALS['dummy1'], $GLOBALS['dummy2'], $GLOBALS['dummy3']);

The second test, "add operator", was:

$array = $GLOBALS['dummy1'] + $GLOBALS['dummy2'] + $GLOBALS['dummy3'];

Running: Linux (x86_64:1 GB) PHP (