Static Class

A static class is a class that only holds static methods, properties or constants.

There is no special syntax for such a class: it is simply created with the abovementioned structures. Other programming languages have a dedicated syntax for them.

A static class is usually used by direct call, with the :: operator. A static class may still be instantiated, though there is little usage for such an object.

<?php

    class X {
        public static int $p = 0;

        public static function increment(): int {
            return self::$p++;
        }
    }

    echo X::increment(); // 1

?>

Documentation

Related : Scope Resolution Operator ::, Static Method, Static Constant, Static Property, Colon