## Test: set unique vs. !isset

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

View test history (1) Run this test again Return to test menu## Result: Saved

The test labeled "**set**" was the faster by

*0.0187*seconds, (2.117% faster)

The **set** test took **0.8628** seconds.

The **!isset()** test took **0.8815** seconds.

## Nitty-Gritty

Each test case ran 20 random code order iterations consisting of 141,293 loops for a total of 2,825,860 runs.

- Line execution difference (0.000007) milliseconds.

- Avg difference (0.933) milliseconds per 141,293 loops.

- Total difference 18.67 milliseconds for 2,825,860 loops

The iteration variablity for Code 1 was (4.0776) milliseconds and Code 2 was (4.0374) 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; }