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
php闭包使用例子
原文地址：https://www.cnblogs.com/fps2tao/p/8855945.html