在PHP中链接静态方法? [英] Chaining Static Methods in PHP?
问题描述
是否可以使用静态类将静态方法链接在一起?说我想做这样的事情:
Is it possible to chain static methods together using a static class? Say I wanted to do something like this:
$value = TestClass::toValue(5)::add(3)::subtract(2)::add(8)::result();
. . .显然我希望将$ value分配给数字14.这可能吗?
. . . and obviously I would want $value to be assigned the number 14. Is this possible?
更新:它不起作用(您不能返回自我"-这不是实例!),但这就是我的想法带给我的地方:
Update: It doesn't work (you can't return "self" - it's not an instance!), but this is where my thoughts have taken me:
class TestClass {
public static $currentValue;
public static function toValue($value) {
self::$currentValue = $value;
}
public static function add($value) {
self::$currentValue = self::$currentValue + $value;
return self;
}
public static function subtract($value) {
self::$currentValue = self::$currentValue - $value;
return self;
}
public static function result() {
return self::$value;
}
}
解决了这个问题之后,我认为只使用类实例而不是尝试链接静态函数调用(除非上面的示例可以通过某种方式进行调整,否则看起来不太可能)会更有意义. /p>
After working that out, I think it would just make more sense to simply work with a class instance rather than trying to chain static function calls (which doesn't look possible, unless the above example could be tweaked somehow).
推荐答案
我喜欢上面Camilo提供的解决方案,基本上是因为您所做的只是更改静态成员的值,并且因为您确实希望链接(甚至尽管它只是一种糖),但是实例化TestClass可能是最好的方法.
I like the solution provided by Camilo above, essentially since all you're doing is altering the value of a static member, and since you do want chaining (even though it's only syntatic sugar), then instantiating TestClass is probably the best way to go.
如果您想限制类的实例化,我建议使用Singleton模式:
I'd suggest a Singleton pattern if you want to restrict instantiation of the class:
class TestClass
{
public static $currentValue;
private static $_instance = null;
private function __construct () { }
public static function getInstance ()
{
if (self::$_instance === null) {
self::$_instance = new self;
}
return self::$_instance;
}
public function toValue($value) {
self::$currentValue = $value;
return $this;
}
public function add($value) {
self::$currentValue = self::$currentValue + $value;
return $this;
}
public function subtract($value) {
self::$currentValue = self::$currentValue - $value;
return $this;
}
public function result() {
return self::$currentValue;
}
}
// Example Usage:
$result = TestClass::getInstance ()
->toValue(5)
->add(3)
->subtract(2)
->add(8)
->result();
这篇关于在PHP中链接静态方法?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!