问题描述
我想知道是否有办法在 PHP 中为新创建的对象链接方法?
I would like to know whether there's a way to chain methods on a newly created object in PHP?
类似于:
class Foo {
public function xyz() { ... return $this; }
}
$my_foo = new Foo()->xyz();
有人知道实现这一目标的方法吗?
Anyone know of a way to achieve this?
推荐答案
在 PHP 5.4+ 中，解析器已被修改，因此您可以执行类似的操作
In PHP 5.4+, the parser's been modified so you can do something like this
(new Foo())->xyz();
将实例化在括号中，并用链子连接起来.
Wrap the instantiation in parenthesis, and chain away.
在 PHP 5.4 之前，当您使用
Prior to PHP 5.4, when you're using the
new Classname();
语法，您不能将方法调用链接到实例化之外.这是 PHP 5.3 语法的限制.一旦对象被实例化，您就可以将其链接起来.
syntax, you can't chain a method call off the instantiation. It's a limitation of PHP 5.3's syntax. Once an object is instantiated, you can chain away.
我见过用来解决这个问题的一种方法是某种静态实例化方法.
One method I've seen used to get around this is a static instantiation method of some kind.
class Foo
{
public function xyz()
{
echo "Called","
";
return $this;
}
static public function instantiate()
{
return new self();
}
}
$a = Foo::instantiate()->xyz();
通过在静态方法中包装对 new 的调用，您可以使用方法调用实例化一个类，然后您就可以自由地将其链接起来.
By wrapping the call to new in a static method, you can instantiate a class with method call, and you're then free to chain off that.
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