title: Compare all NSStrings with Core Data
body: <p>In my app are categories and in the categories are cell that contains information. The user can add a category and in a category the user can add a cell with information.
  You can change the style of the cell with information with a <code>UISwitch</code> that sets a <code>NSString</code> to <code>@"ON"</code> or <code>@"OFF"</code> and the with a if statement do I check if the NSString is equal to <code>@"ON"</code> or <code>@"OFF"</code>. This all is saved in Core Data.<br>
  Now I want when <b>all</b> the cells with information in a specific category has the <code>NSString</code> <code>@"ON"</code> that the style of the categorycell change.
  I can change the style, but I don't know how I can compare if <b>all</b> the <code>NSString</code>s are equal to <code>@"ON"</code>.</p>
  
  <p>Can anyone help me?</p>
  
  <p><strong>Edit:</strong><br>
  I use two entities (one for the categories and one for the cells with information).
  In the entity for category is a attribute with the name <code>donelist</code> and the type is a string.
  In the entity for the information is a attribute with the name <code>doneinfo</code> and the type is also a string.</p>
  
  <p>The goal is to change the style (dequeueReusableCellWithIdentifier) if all the information in the category is set to <code>@"ON"</code>.
  I mean with style that the color is changed.
  I had do this with an identifier, but that is not the big problem.
  The problem is that I don't know how I can check if all the information in a category is done (the NSString is set to <code>@"ON"</code>).</p>