致命错误：找不到“ App \\ PDO”类

Question

I get this error when I try to use namespaces.

I have

namespace App;

the top, and the class looks like

class database{

  function __construct(..)
    try{
      $this->db = new PDO(...)   <-- here the error
    ...
  }
}

I dont' understand how do namespaces work? Shouldn't PHP fallback to the default PDO class if app/PDO is not found?

Answer 1

Shouldn't PHP fallback to the default PDO class if app/PDO is not found?

No, it should not.

From the documentation :

Class names always resolve to the current namespace name. Thus to access internal or non-namespaced user classes, One must refer to them with their fully qualified Name

For your specific example, the fully qualified name for PDO would be \\PDO .

Answer 2

Just add use PDO; after the namespace and before the class.