title: condition in function parameter
body: <p>I'm new in C#. I would like to check some condition in function parameter.</p>
  
  <p>I have to write function which in their parameter will check which numbers are greater than zero and return this numbers. How to solve it?</p>
  
  <p>I have tried in many ways but none work.</p>
  
  <p>Below is the code I have:</p>
  
  <p><code>int[] arr = new int[] {2, 3, -5};</code></p>