title: Changing The value of struct in an array
body: <p>I want to store structs inside an array, access and change the values of the struct in a for loop. </p>
  
  <pre><code>struct testing {
      var value:Int
  }
  
  var test1 = testing(value: 6 )
  
  test1.value = 2
  // this works with no issue
  
  var test2 = testing(value: 12 )
  
  var testings = [ test1, test2 ]
  
  for test in testings{
      test.value = 3
  // here I get the error:"Can not assign to 'value' in 'test'"
  }
  </code></pre>
  
  <p>If I change the struct to class it works. Can anyone tell me how I can change the value of the struct.</p>