一.依据闭包实现一个容器

class Di{    private $factory;     public function set($id, $value)    {        $this->factory[$id] = $value;    }     public function get($id)    {        $val = $this->factory[$id];        return $val();//如果不加括号,仅仅返回的是闭包类,并不是User实例    }} class User{    private $username;     public function __construct($username = '')    {        $this->username = $username;    }     public function getUserName()    {        return $this->username;    }} $di = new Di(); // 在此使用了闭包,所以实际上并不会实例化User类,只有在后面get的时候才会实例化$di->set('a', function(){    return new User('张三');}); var_dump($di->get('a')->getUserName());

二.使用闭包作为回调

class Cart{    CONST PRICE_BUTTER = 1.0;    CONST PRICE_MILK = 5.05;     protected $products = [];     public function add($product, $quantity)    {        $this->products[$product] = $quantity;    }     public function getQuantity($product)    {        return isset($this->products[$product]) ? $this->products[$product]: false;    }     public function getTotal($tax)    {        $total = 0.00;        $callback = function($quantity, $product) use ($tax, &$total) {            $priceItem = constant(__CLASS__ . '::PRICE_' . strtoupper($product));            $total += ($priceItem * $quantity) * ($tax + 1.0);        };         array_walk($this->products, $callback);        return round($total, 2);    }} $cart = new Cart();$cart->add('butter', 1);$cart->add('milk', 5); echo $cart->getTotal(0.05);

三.使用闭包函数调用类中方法

class Grid{    protected $builder;    protected $attribute;     public function __construct(Closure $builler)    {        $this->builder = $builler;    }     public function addColumn($name, $value)    {        $this->attribute[$name] = $value;        return $this;    }     public function build()    {        // 这儿回调闭包函数,参数为this        call_user_func($this->builder, $this);    }     public function __toString()    {        $this->build();         $str = '';        $call = function($val, $key) use(&$str) {             $str .= "$key=>$val;";        };        array_walk($this->attribute, $call);         return $str;    }} $grid = new Grid(    // 传入闭包函数,带参数    function($grid) {        $grid->addColumn('key1', 'val1');        $grid->addColumn('key2', 'val2');    }); echo $grid;

 

 

 

 

关联文章:http://www.cnblogs.com/fps2tao/p/8727482.html

 

转:https://www.cnblogs.com/itfenqing/p/7073307.html