Obtenha a primeira chave de matriz php
$firstKey = array_key_first($array);
butterfly
$firstKey = array_key_first($array);$colors = array(2=>"blue",3 =>"green",1=>"red");
$firstValue = reset($colors); //blue
$firstKey = key($colors); //2For PHP version 7 and above
$array = array(
"1" => "PHP code tester Sandbox Online",
"foo" => "bar",
"case" => "Random Stuff: " . rand(100,999),
"PHP Version" => phpversion()
);
$firstValue = reset($colors); // PHP code tester Sandbox Online
$firstKey = key($colors); // 1