How to fix a problem with namespace?

Used to useyii2 basic, and no problems!

But now we need to use advanced, but it is a problem!

Why there is error with namespace, the system simply does not see them!

example index.php in frontend:

2831cc8fe3db46038eb80b327efa66e0.png
How can I fix it ?
July 8th 19 at 16:32
2 answers
July 8th 19 at 16:34
To write yii\helper and \yii\helper
No, that's the same problem. - tristian_Maggio commented on July 8th 19 at 16:37
July 8th 19 at 16:36
Given that You write in the storm, I would recommend to remove the namespace of the calling class.
Then You have the class itself will be highlighted in yellow (as it is now on the screen), and press alt-enter and import the class use the block.
Did so, but the storm only offers to create this class. - tristian_Maggio commented on July 8th 19 at 16:39
And you installed all dependencies? composer install

Or check that the vendor folder was not excluded from the project.
And even better excluded from the project activity and connected to the include path.

I hope not confused) - tristian_Maggio commented on July 8th 19 at 16:42

Find more questions by tags PHPYii