title: OOP Array filtering using a string?
body: <p>So I'm pretty new to C# OOP and I'm just getting the hang of this style of programming at college and I've come across arrays. Now, I understand how to create them and their general use, but I don't understand how I would filter them using a string.</p>
  
  <p>For a little back story this is part of what I have been asked to do;</p>
  
  <p>In part of my project I needed to create three arrays, set out the topic information and then output it to the user with a display method. I was also required to use the _findExamIndex (Searches the exams array for results based on an exam id given) to list the exams, to then use the _findStudentIndex (Searches a list of students for a student) to be able to select a individual students results. </p>
  
  <p>The problem I am having issues is with  filtering  the results of the _exams array with the string _topicName, I'm unsure as to how to go about doing that as I am new to using arrays as a way of storing data and would greatly appreciate a little help, many thanks.</p>
  
  <p>(Method code)    </p>
  
  <pre><code>public void viewTopicsResults(string _topicName,List&lt;Results&gt; _results, List&lt;Student&gt; _students, Exam[] _exams, DisplayClass.Display _theDisplay)
  {
          int[] columnWidths = { 3, 20 };
          char[] charactersInTheSpaces = { ' ', ' ' };
          string[] topicInfo = new string[6];
  
          topicInfo[0] = "Student";
          topicInfo[1] = "Subject";
          topicInfo[2] = "Topic";
          topicInfo[3] = "Style";
          topicInfo[4] = "Date";
          topicInfo[5] = "Score";
  
  
          //Ordering the table by topic.      
          _theDisplay.writeLineWithTab(topicInfo, columnWidths, charactersInTheSpaces);
  
  
          foreach(Results result in _results)
          {
              int examID = _theDisplay.userInputAsInteger("Select a result");
              _findExamIndex(examID, _exams);
               int studentID = _theDisplay.userInputAsInteger("Please select a users result");
              _findStudentIndex(studentID, _students);
  
               //filter on the _exams' Topic == '_topicName'
  
          }
  }
  </code></pre>
  
  <p>(This method will be called by the main method)</p>