Difference between object reference declaration and object construction?
<p>Consider a class named <code>Calculator</code> with the following code:</p>

<pre><code>class Calc extends Calculator {

    Calculator calculator;                    // [Style 1]

    Calculator calculator = new Calculator(); // [Style 2]
}
</code></pre>

<p>To my knowledge, no memory has been allocated in <code>[1]</code>, but in statement <code>[2]</code> a new <code>Calculator</code> object is created.</p>

<p>Are there any other differences beyond that?</p>
