$arr = [
"Python 4", "C 9", "C++ 5", "C# 6",
"Java 1", "PHP 7", "Go 2"
];
function extractName(string $s): string {
$pos = strrpos($s, ' ');
return substr($s, 0, $pos);
}
usort($arr, function($a, $b) {
return extractName($a) <=> extractName($b);
});
print_r($arr);
/*
run:
Array
(
[0] => C 9
[1] => C# 6
[2] => C++ 5
[3] => Go 2
[4] => Java 1
[5] => PHP 7
[6] => Python 4
)
*/