1. Implement a container based on closures
class Di { private $factory; public function set($id, $value) { $this->factory[$id] = $value; } public function get($id) { $val = $this ->factory[ $id ]; return $val (); // If the parentheses are not added, only the closure class is returned, not the User instance } } class User { private $username; public function __construct($username = '') { $this->username = $username; } public function getUserName() { return $this->username; } } $di = new Di(); // The closure is used here, so the User class is not actually instantiated. It is only instantiated when get later $di ->set('a', function (){ return new User(' Zhang three' ); }); var_dump($di->get('a')->getUserName());
2. Use closures as callbacks
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);
3. Use the closure function to call the method in the class
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() { // The callback closure function here, the parameter is 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( // pass in a closure function with parameters function ( $grid ) { $grid ->addColumn('key1', 'val1' ); $grid ->addColumn('key2', 'val2' ); } ); echo $grid;
Related articles: http://www.cnblogs.com/fps2tao/p/8727482.html
Transfer: https://www.cnblogs.com/itfenqing/p/7073307.html