php静态属性

class Counter {
    public static $count = 0;

    public function increment() {
        self::$count++;
    }

    public function getCount() {
        return self::$count;
    }
}

// 使用静态属性
Counter::increment();
Counter::increment();
echo Counter::getCount(); // 输出 2

class Example {
    public static $staticVar;

    public static function clearStaticVar() {
        unset(self::$staticVar);
    }
}

Example::$staticVar = 'some value';
Example::clearStaticVar();

class ThreadSafeCounter {
    private static $count = 0;
    private static $lock;

    public static function increment() {
        if (self::$lock === null) {
            self::$lock = fopen('lockfile', 'w');
        }
        flock(self::$lock, LOCK_EX);
        self::$count++;
        flock(self::$lock, LOCK_UN);
    }

    public static function getCount() {
        return self::$count;
    }
}