variable definition in php without @

Hello

As you know, if an empty variable is defined, it gives an error and must be preceded by @.

I have seen systems where the variable is defined as empty. @ It was not necessary and it did not give an error.
And I don't want to use these items:
error_reporting and display_errors and display_startup_errors

Is there a code and is it possible to define an empty variable and not use @!?

And sorry that my language is weak
thank you