类中的复杂变量名

Question

I noticed that some people use variable names like these inside their classes:

private $_some_long_name_;

public static $_____foo___;

Why?

Shoudn't these variables be able to be accessed only trough class::variable, $this->variable or self::variable ? So you can't have a conflict between between them and other variables with the same name, right?

Answer 1

Because they don't want to confuse both variables accidentally. However, you're right, it's not necessary