命名空间 - __autoload（）需要一个错误的类

Question

I am builded a new object in my file without namespaces:

new My\Validator();

Above, in the same file I have got __autoload():

function __autoload($className) 
{
    var_dump($className);
}

The __autoload() function prints

'My\My\Validator'.  

Where is the double 'My' come from?

Answer 1

It is adding the My namespace because you are probably inside the My namespace already when you create the object with new My\Validator().

namespace My;
$obj = new My\Validator();

will be translated to:

$obj = new My\My\Validator();

Since you are inside the My namespace already you can:

• either just call new Validator()
• or call new \My\Validator()

The beginning \ will tell PHP to look into the global namespace.

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On a side note, it is considere good practice to use spl_autoload_register instead of __autoload, because you can set multiple autoloader callbacks.