title: How would I create a constant that could be one of several strings depending on conditions?
body: <p>I want to have a constant using <code>let</code> that may be one of several values.</p>
  
  <p>For instance:</p>
  
  <pre><code>if condition1 {
     constant = "hi"
  }
  else if condition2 {
     constant = "hello"
  }
  else if condition3 {
     constant = "hey"
  }
  else if condition4 {
     constant = "greetings"
  }
  </code></pre>
  
  <p>I'm not sure how to do this with Swift and the <code>let</code> feature. But I'm inclined to believe it's possible, as this is in the Swift book:</p>
  
  <blockquote>
    <p>Use let to make a constant and var to make a variable. The value of a constant doesn’t need to be known at compile time, but you must assign it a value exactly once.</p>
  </blockquote>
  
  <p>How would I accomplish this?</p>