title: swift3 How to remove Optional
body: <p>this is my code:</p>
  
  <pre><code> func uplouadPost() {
  
      // shortcut to data to be php
  
     let parseJSON = UserDefaults.standard.value(forKey: "parseJSON") as? 
     NSDictionary
     let userID = parseJSON!["userID"] as! String
  </code></pre>
  
  <p>....</p>
  
  <pre><code>  if error == nil {
  
              do {
  
                  // json containes $returnArray from php
                  let json = try JSONSerialization.jsonObject(with: data!, 
    options: .mutableContainers) as? NSDictionary
  
                  print("========================\(userID)")      
  </code></pre>
  
  <p>print I get ========================Optional(23)</p>
  
  <p>But I don't want Optioanl</p>
  
  <p>how to just get 23</p>
  
  <p>What's more, I tried to unwrap the "userID" by this way. However it doesn't work</p>
  
  <pre><code>let unwrappedUserID = [userID]
  
  print (unwrappedUserID)
  </code></pre>
  
  <p>Thank you guys</p>