## Test: set duplicates vs. !isset

This checks the cost of writing vs. the cost of checking if you're already written - for values that commonly overlap.

Run this test again Return to test menu## Historical Results

Based on (2) saved test runs, The test labeled "**!isset()**" was (on average) the faster by

*0.0074*seconds, (0.942% faster)

The **!isset()** test took **0.7769** seconds.

The **set** test took **0.7843** seconds.

## Nitty-Gritty

Each test case ran 20 random code order iterations consisting of 191,425 loops for a total of 3,828,500 runs.

- Line execution difference (0.000002) milliseconds.

- Avg difference (0.000) milliseconds per 191,425 loops.

- Total difference 7.39 milliseconds for 3,828,500 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, "**set**", was:

$array = array(); for ($n = 0; $n < 100; $n++) { $k = floor($n / 12); $array[$k] = $n + 42; }

The second test, "**!isset()**", was:

$array = array(); for ($n = 0; $n < 100; $n++) { $k = floor($n / 12); if (!isset($array[$k])) $array[$k] = $n + 42; }