Retrieve Highest Value from Array in PHP - php

Question

I would post the entire code, but it is lengthly and confusing, so I'll keep it short and simple. This is complicated for myself, so any help will be greatly appreciated!
These are the values from my Array:
Light Blue1
Blue2
Blue1
Black3
Black2
Black1
The values I need to retrieve from my Array are "Light Blue1", "Blue2" and "Black3". These are the "highest values" for each color.
Something similar to what I'm looking for is array_unique, but that wouldn't work here. So something along those lines that can retrieve each color with its highest number.
Thanks!

Answer 1

Assuming your format is always NameNumber a regex should do the trick for separating the data. This will loop through your data in the order your provide and grab the first element that is different and put it into $vals. I am also assuming your data will always be ordered as your example shows
$data = ['Light Blue1',
'Blue2',
'Blue1',
'Black3',
'Black2',
'Black1'];
$vals = [];
$current = '';
foreach($data as $row) {
if(!preg_match('/(.*)(\d)/i', $row, $matched)) continue;
if($matched[1] != $current) {
$vals[] = $row;
$current = $matched[1];
}
}

Answer 2

The solution using preg_split and max functions:
$colors = ['Light Blue1', 'Blue2', 'Blue1', 'Black3', 'Black2', 'Black1'];
$unique_colors = $result = [];
foreach ($colors as $k => $v) {
$parts = preg_split("/(\d+)/", $v, 0, PREG_SPLIT_DELIM_CAPTURE);
$unique_colors[$parts[0]][] = (int) $parts[1];
}
foreach ($unique_colors as $k => $v) {
$result[] = $k . max($v);
}
print_r($result);
The output:
Array
(
[0] => Light Blue1
[1] => Blue2
[2] => Black3
)

Answer 3

If you pre-sort your array with "natural sorting", then you can loop through the array and unconditionally push values into the result with digitally-trimmed keys. This will effectively overwrite color entries with lesser number values and only store the the highest numbered color when the loop finishes.
Code: (Demo)
natsort($data);
$result = [];
foreach ($data as $value) {
$result[rtrim($value, '0..9')] = $value;
}
var_export(array_values($result));
Or you could parse each string and compare the number against its cached number (if encountered before): (Demo)
$result = [];
foreach ($data as $value) {
sscanf($value, '%[^0-9]%d', $color, $number);
if (!isset($result[$color]) || $result[$color]['number'] < $number) {
$result[$color] = ['value' => $value, 'number' => $number];
}
}
var_export(array_column($result, 'value'));
A related technique to find the highest value in a group