title: Centering label with constraints in XCode Interface Builder
body: <p>I'm trying to center a label in the Interface Builder in XCode 6. Here's what I do:</p>
  
  <ol>
  <li>Click on 'Hello World' label and add height and width constraint</li>
  <li>Click on the same label and click on the 'Align' constraint. Check the Horizontal and Vertical align in container.</li>
  <li>When I run it, the label is in the top-left corner. Why isn't it centered?</li>
  </ol>
  
  <p>Below are some images of what I'm looking at:</p>
  
  <p><img src="https://i.stack.imgur.com/hJz4H.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/or4bq.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/izdxk.png" alt="enter image description here"></p>