elementos de matriz de contagem de php com chave específica
$cnt = count(array_filter($array,function($element) {
return $element['your_key']=='foo';
}));
Matteoweb
$cnt = count(array_filter($array,function($element) {
return $element['your_key']=='foo';
}));$tmp = array_count_values($uid);
$cnt = $tmp[12];
//Or
$cnt = count(array_filter($uid,function($a) {return $a==12;}));
//In both cases $var will be a number