search to specific array key

[fesan]

Hi, is there possible to search and "choose" a certain arrey key by user input? And when the input is not "korrect" how to choose the closest one?

 

Input = 22

 

$kz should chose key 21.3 => 1.17

$kz = array(
4.6 => 0.85,
6.1 => 0.90,
7.6 => 0.94,
9.1 => 0.98,
12.2 => 1.04,
15.2 => 1.09,
18 => 1.13,
21.3 => 1.17,
24.4 => 1.21,
27.4 => 1.24,
30.5 => 1.26,
36.6 => 1.31,
42.7 => 1.36,
48.8 => 1.39,
54.9 => 1.43,
61.0 => 1.46,
76.2 => 1.53,
91.4 => 1.59,
106.7 => 1.64,
121.9 => 1.69,
137.2 => 1.73,
152.4 => 1.77,); 

To explain some more, the array is part of a math solving. where the key is a height in meters and the value are the responding coefficient. 

$qz = 0.613 * $kz * 1 * 1 * pow($vind2, 2) *1;

 

[CroNiX]

I don't believe you can the way you have it.

 

You can't use decimal numbers as array keys. If I copy/paste your $kz array and just print_r($kz), you get back whole numbers for the array indices instead of your decimals (24.4 becomes just 24).

 

If your keys were strings containing a decimal, then it could be workable.

[requinix]

Make sure $kz is sorted, then foreach until the previous key = desired key. If it's not an exact match then pick whichever of the previous and current keys is closest.