title: How to trim a String using Swift 3
body: <p>My code snippet is: </p>
  
  <pre><code>unwanted = " £€₹jetztabfromnow"
  
  let favouritesPriceLabel = priceDropsCollectionView.cells.element(boundBy: UInt(index)).staticTexts[IPCUIAHighlightsPriceDropsCollectionViewCellPriceLabel].label
  let favouritesPriceLabelTrimmed = favouritesPriceLabel.components(separatedBy: "jetzt").flatMap { String($0.trimmingCharacters(in: .whitespaces)) }.last
  
  favouritesHighlightsDictionary[favouritesTitleLabel] = favouritesPriceLabelTrimmed
  </code></pre>
  
  <p>My problem is, this didn't work: </p>
  
  <pre><code>let favouritesPriceLabelTrimmed = favouritesPriceLabel.components(separatedBy: unwanted).flatMap { String($0.trimmingCharacters(in: .whitespaces)) }.last
  </code></pre>
  
  <p>I have a price like "from 3,95 €" - I want to cut all currencies "£€₹" and words like "from" or "ab"</p>
  
  <p>Do you have a solution for me, what I can use here?</p>