## Test: set unique vs. !isset

This checks the cost of checking if you're already written a value when that's never true.

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

Based on (1) saved test runs, The test labeled "**set**" was (on average) the faster by

*0.0238*seconds, (2.005% faster)

The **set** test took **1.165** seconds.

The **!isset()** test took **1.1888** seconds.

## Nitty-Gritty

Each test case ran 20 random code order iterations consisting of 279,527 loops for a total of 5,590,540 runs.

- Line execution difference (0.000004) milliseconds.

- Avg difference (0.000) milliseconds per 279,527 loops.

- Total difference 23.83 milliseconds for 5,590,540 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 = $n; $array[$k] = $n + 42; }

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

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