title: How to make an array string from enum member raw value in swift
body: <p>I am new in programming and swift. I have an enum like this</p>
  
  <pre><code>enum City : String {
      case tokyo = "tokyo"
      case london = "london"
      case newYork = "new york"
  }
  </code></pre>
  
  <p>Could I possibly get that city name to an array from enum raw value? I hope I can get something like this :</p>
  
  <pre><code>let city = ["tokyo","london","new york"]
  </code></pre>