php - working - Troubleshooting “The use statement with non-compound name … has no effect”

the use statement with non-compound name has no effect laravel (4)

Getting this error when I put use Blog; at the top.

Warning: The use statement with non-compound name 'Blog' has no effect in...

Blog is my namespace in which I have 3 classes: Article, List and Category and a few functions.

If I change my statememnt to use Blog\Article; then it works...

Can't I just specify the namespaces I want to use? Do I need to provide classes?

What if I have functions within that namespaces? When I call them outside of the namespace, I'm forced to prepend \Blog\ to each one's name...

PHP's use isn't the same as C++'s using namespace; it allows you to define an alias, not to "import" a namespace and thus henceforth omit the namespace qualifier altogether.

So, you could do:

use Blog\Article as BA;

... to shorten it, but you cannot get rid of it entirely.

Consequently, use Blog is useless, but I believe you could write:

use \ReallyLongNSName as RLNN;

Note that you must use a leading \ here to force the parser into knowing that ReallyLongNSName is fully-qualified. This isn't true for Blog\Article, which is obviously already a chain of namespaces:

Note that for namespaced names (fully qualified namespace names containing namespace separator, such as Foo\Bar as opposed to global names that do not, such as FooBar), the leading backslash is unnecessary and not recommended, as import names must be fully qualified, and are not processed relative to the current namespace.

Since this question appears as the first result on Google for this error I will state how I fixed it.

Basically if you have a framework, say like Yii2 you will be used to having to do declare classes like:

use Yii;
use yii\db\WhatEver;

class AwesomeNewClass extends WhatEver

You will get this error on Use Yii since this class has no namespace.

Since this class has no namespace it automatically inherits the global symbol table and so does not need things like this defining, just remove it.

The error "The use statement ... has no effect..." also pops up if you try to use a trait before a class definition.

use My_trait; // should not be here

class My_class{
// use My_trait; should be here instead

if you don't want to use 'as' syntax like

use \Blog as B;

define a namespace for the file

namespace anyname;

use Blog