title: Solidity : How does function parameters' size affects gas cost?
body: <p>before anything here's some context : </p>
  
  <p><em>Let's say I'm implementing a dApp, and I want to reduce the number of times users have to call the related smart-contract. In order to do this, all the users' actions are stacked-up, client-side. Eventually, users will have to commit their actions to the smart-contract, in order to update their datas on chain.</em></p>
  
  <p>The smart-contract takes a queue of all the users' actions as a parameter, and iterate over it to do mainly some checkings and update.
  A bit like this : </p>
  
  <pre><code>function verifyUsersActions(Queue actions) public
  {
      while(actions.length != 0)
      {
          Action currentAction = actions.pop(); 
              /* tests on currentAction, update datas, etc */
      }
  }
  </code></pre>
  
  <p><strong>My question is</strong>: how does the size of the "actions" object affects gas cost ? 
  What's the increment in gas, between an "actions.length = 2" and an "actions.length = 3" ? </p>
  
  <p>I'm still confused with  "<em>memory</em>" and "<em>storage</em>" variables, and don't know in which category does function call parameters fall in.</p>