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.

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Historical Results

Based on (3) saved test runs, The test labeled "add operator" was (on average) the faster by 0.0257 seconds, (3.631% faster)

add operator 100%
array_merge() 96.369%

The add operator test took 0.6831 seconds.
The array_merge() test took 0.7088 seconds.


Each test case ran 20 random code order iterations consisting of 153,110 loops for a total of 3,062,207 runs.

  • Line execution difference (0.000008) milliseconds.
  • Avg difference (0.000) milliseconds per 153,110 loops.
  • Total difference 25.74 milliseconds for 3,062,207 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.


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 (