如何访问在 php 中命名为变量(点表示法)的深层对象属性?

问题描述

有很多与此类似的问题，但这里略有不同，因为它是关于深度对象属性访问的，而不仅仅是一层深度.

There are many questions similar to this, however this is slightly different since it's about deep object property access, not just one level of depth.

假设我有一个包含字符串 foo.bar 的变量.

Let's say I have a variable containing the string foo.bar.

$user = new User();
$user->foo = new Foo();
$user->foo->bar = "Hello World";

$variable = "foo.bar"

我想通过使用 $variable 来回显 $user->foo->bar:

I would like to echo $user->foo->bar by making use of $variable:

echo $user->foo->bar

这是我迄今为止尝试过但没有成功的方法(它说 NULL):

This is what I have tried so far but with no success (it says NULL):

$value = str_replace(".", "->", $value);
echo $user->{$value};

推荐答案

使用可变属性符号($o->$p减少对象路径非常容易代码>):

$path = 'foo.bar';
echo array_reduce(explode('.', $path), function ($o, $p) { return $o->$p; }, $user);