PHP class name::class meaning

Since PHP 5.5, the keyword class can also be used for class name resolution.

Use ClassName::class to get a string containing the fully qualified name of the class ClassName. This is especially useful for classes that use namespaces.

<?php
namespace ddd\vector;

class Demo
{
    
    

    public function test()
    {
    
    
        // code...
    }
}

echo Demo::class; //ddd\vector\Demo

?>