Swift 代码：

class CompositeDemo {
    struct Employee: Hashable {
        let name: String
        let dept: String
        let salary: Int
        var subordinates: [Employee] = []

        init(name: String, dept: String, salary: Int) {
            self.name = name
            self.dept = dept
            self.salary = salary
        }

        mutating func add(_ item: Employee) {
            subordinates.append(item)
        }
        mutating func remove(_ item: Employee) {
            if let index = subordinates.firstIndex(of: item) {
                subordinates.remove(at: index)
            }
        }
    }

    func execute() {
        var CEO = Employee(name: "John",dept: "CEO", salary: 30000)
        var headSales = Employee(name: "Robert",dept: "Head Sales", salary: 20000)
        var headMarketing = Employee(name: "Michel",dept: "Head Marketing", salary: 20000)

        let clerk1 = Employee(name: "Laura",dept: "Marketing", salary: 10000)
        let clerk2 = Employee(name: "Bob",dept: "Marketing", salary: 10000)
        let salesExecutive1 = Employee(name: "Richard",dept: "Sales", salary: 10000)
        let salesExecutive2 = Employee(name: "Rob",dept: "Sales", salary: 10000)

        CEO.add(headSales)
        CEO.add(headMarketing)
        headSales.add(salesExecutive1)
        headSales.add(salesExecutive2)
        headMarketing.add(clerk1)
        headMarketing.add(clerk2)

        //打印该组织的所有员工
        print(CEO)
        for headEmployee in CEO.subordinates {
            print(headEmployee)
            for employee in headEmployee.subordinates {
                print(employee)
            }
        }
    }
}

PHP 实现：

/**
 * Class Employee
 * 雇员类
 */
class Employee
{
    private $_name;
    private $_dept;//部门
    private $_salary;//薪水
    private $_subordinates;//下属

    public function __construct(string $name, string $dept, int $sal)
    {
        $this->_name = $name;
        $this->_dept = $dept;
        $this->_salary = $sal;
        $this->_subordinates = [];
    }

    public function add(Employee $employee)
    {
        array_push($this->_subordinates, $employee);
    }

    public function remove(Employee $employee)
    {
        $this->_subordinates = array_filter($this->_subordinates, function ($v) use ($employee) {
            return ($employee != $v);
        });
    }

    public function getSubordinates()
    {
        return $this->_subordinates;
    }

    public function __toString()
    {
        // TODO: Implement __toString() method.
        return "Employee: [name: " . $this->_name . ",dept: " . $this->_dept . ",salary: " . $this->_salary . "]";
    }
}

class Demo
{
    public static function main()
    {
        $CEO = new Employee("John", "CEO", 30000);
        $headSales = new Employee("Robert", "Head Sales", 20000);
        $headMarketing = new Employee("Michel", "Head Marketing", 20000);
        $clerk1 = new Employee("Laura", "Marketing", 10000);
        $clerk2 = new Employee("Bob", "Marketing", 10000);
        $salesExecutive1 = new Employee("Richard", "Sales", 10000);
        $salesExecutive2 = new Employee("Rob", "Sales", 10000);

        $CEO->add($headSales);
        $CEO->add($headMarketing);

        $headSales->add($salesExecutive1);
        $headSales->add($salesExecutive2);

        $headMarketing->add($clerk1);
        $headMarketing->add($clerk2);

        echo $CEO . PHP_EOL;
        $headMarketing->remove($clerk2);

        foreach ($CEO->getSubordinates() as $employee) {
            echo '-' . $employee . PHP_EOL;
            foreach ($employee->getSubordinates() as $e) {
                echo '---' . $e . PHP_EOL;
            }
        }
    }
}

Demo::main();