When should I declare variables in a PHP class?
oop, php
Solution
That variable isn't uninitialized, it's just undeclared.
Declaring variables in a class definition is a point of style for readability. Plus you can set accessibility (private or public).
Anyway, declaring variables explicitly has nothing to do with OOP, it's programming-language-specific. In Java you can't do that because variables must be declared explicitly.
Problem
I'm new to the OOP paradigm, so there's probably a simple explanation for this question... Do you always need to declare public object-wide variables in a class? For example: ``` <?php class TestClass { var $declaredVar; function __construct() { $this->declaredVar = "I am a declared variable."; $this->undeclaredVar = "I wasn't declared, but I still work."; } function display() { echo $this->declaredVar . "<br />"; echo $this->undeclaredVar; echo "<br /><br />"; } } $test = new TestClass; $test->display(); $test->declaredVar = "The declared variable was changed."; $test->undeclaredVar = "The undeclared variable was changed."; $test->display(); ?> ``` In this code, even though `$declaredVar` is the only declared variable, `$undeclaredVar` is just as accessible and useable--it seems to act as if I had declared it as public. If undeclared class variables are always accessible like that, what's the point of declaring them all up front?