gistfile1.php

<?php
/**
 * The only function of this statement is to return $poll_id if it's set. Which
 * snippet would you use and why?
 *
 * I (@jrtashjian) prefer and wrote snippet 1. I like how contained the
 * function is, and the fact I'm only calling the post() function once.
 *
 * Each snippet works correctly, this is just preference. I find it redundant
 * to call the post() function more than once (as shown in snippet 3). I also
 * find it unnecessary to create a variable ($poll_id) to store the result of
 * function post() when I'll only be using it for the if statement.
 *
 * Let me know on Twitter, @jrtashjian.
 */

// Snippet 1
if( $poll_id = $this->EE->input->post('poll_id') )
{
	return $poll_id;
}

// Snippet 2
$poll_id = $this->EE->input->post('poll_id');
if( $poll_id )
{
	return $poll_id;
}

// Snippet 3
if( $this->EE->input->post('poll_id') )
{
	return $this->EE->input->post('poll_id');
}

return ($poll_id = $this->EE->input->post('poll_id')) ? $poll_id : false;

I probably should have said that this is a statement which short-circuits a function if $poll_id is set. So, if $poll_id is not set, the function continues to run.

So, you are right in that syntax if it's the final return statement. Wouldn't work for this instance (which I should have stated) but I would absolutely use this in the right circumstances.