wp-includes/Requests/src/Utility/InputValidator.php:39Verify whether a received input parameter is usable as an integer array key.
$inputmixedbool public static function is_numeric_array_key($input) { if (is_int($input)) { return true; } if (!is_string($input)) { return false; } return (bool) preg_match('`^-?[0-9]+$`', $input); }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/Requests/src/Utility/InputValidator.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.