title: Swift: Convert index to int
body: <p>I am new to swift development. Actually it is a simple problem but I cannot figure it out.
  I have a String variable "name1" where I want to determine the position in the alphabet for each character and sum these positions. Therefore I loop through the string and use indexOf() for every character</p>
  
  <pre><code>let name1="myname"
  let sumPositions=0
  
  for index in 0...name1.characters.count-1{
  sumPositions+="ABCDEFGHIJKLMNOPQRSTUVWXYZ".characters.indexOf(name1.startIndex+index);
  }
  </code></pre>
  
  <p>I get the error "Binary operator "+" cannot be applied to operands of type 'index' aka 'String.characterView.index' and 'Int'.
  This means I have to cast 'index' to 'Int' but I did not find a solution for this.</p>