OOP question

PHP
1

Im a bit confused about setting Class attributes. If you have a private attribute at the start of a class you can set it when running a Class method e.g.

class Test {
private $attribute

public function test_function() {
$variable = 3;
$variable = $this->attribute;
}
}

Later you can use the private $attribute in another method by using $this->attribute.

However i have just tested some code i am working on and deleted the private $attribute at the start of the class but i could still use it in a new method by using $this->attribute. Does this mean that i dont need to store values in attributes if i want to use them somewhere else within a class? And if so, what are attributes actually used for?

Thanks

2

Yes, you can call an attribute that is not explicitly declared and PHP will just use it as if it was declared.

The advantage of explicitly declaring them is that:

  1. You (and your colleagues!!) know they exist by looking at the start of the class
  2. You can set a visibility, i.e., public, protected or private; implicitly created variables are public IIRC.

So, even though you can use variables without declaring them, I wouldn’t recommend it.

3

Thanks Scallio, that clears it up.