Problems with the use of namespace and use (detailed examples are attached)

There are two php files in the same directory

Question:
How do I call the static methods of class a and class b in index.php respectively in class c in indexb.php?
How to fill in namespace and use?
File 1: index.php

<code>namespace {
    use 
   class a{
    static public function speak($a)
        {
            echo $a;
        }
   }

}
namespace {
use
    class a{
    static public function speak($a)
        {
            echo $a.$a;
        }
   }

}
</code>

File 2: indexb.php

<code>namespace Php {
    class c
    {
       
    }
}</code>

Reply content:

There are two php files in the same directory

Question:
How do I call the static methods of class a and class b in index.php respectively in class c in indexb.php?
How to fill in namespace and use?
File 1: index.php

<code>namespace {
    use 
   class a{
    static public function speak($a)
        {
            echo $a;
        }
   }

}
namespace {
use
    class a{
    static public function speak($a)
        {
            echo $a.$a;
        }
   }

}
</code>

File 2: indexb.php

<code>namespace Php {
    class c
    {
       
    }
}</code>

File index.php:

<code><?php
namespace A{
   class A{
       static public function speak($a)
       {
           echo $a;
       }
   }

}
namespace  B{
    class B{
        static public function speak($a)
        {
            echo $a;
        }
    }

}</code>

File indexb.php

<code><?php
namespace PHP{
    use A\A;
    use B\B;
    class C{
        public static function test(){
            include "index.php";
            A::speak("I am A!");
            B::speak("I am B!");
        }
    }
    //测试
    \PHP\C::test();
}</code>

Run indexb.php and the result is I am A! I am B!

Is this the result you want?

index.php

<code><?php

namespace test{

class a
{
    static public function speak($a)
    {
        echo $a;
    }
}
}

namespace test2{

class b 
{
    static public function speak($a)
    {
        echo $a.$a;
    }
}
}</code>

indexb.php

<code><?php

namespace testt{

include 'index.php';
use test\a;
use test2\b;

class c
{
    public $a;
    public function speak()
    {
//        var_dump(new a);
//        \test\a::speak($this->a);
        a::speak($this->a);
//        \test2\b::speak($this->a);
        b::speak($this->a);
    }
}

$c = new \testt\c();
$c->a = 'zhansan';
$c->speak();
}</code>