title: Count frequency of string in string array
body: <p>I have list of usernames (string). Each name
  cn[i] will have several skills attached to it:</p>
  
  <pre><code>cn[0] has: "text1, text2, text3"
  cn[1] has: "text2, text4, text6"
  cn[2] has: "text6, text8"
  cn[2] has: "text11, text8, text1, text4, text2"
  </code></pre>
  
  <p>etc.</p>
  
  <p>Now I need to count how many skills in total and each skill how many people have.
  So I think it will contain following steps:</p>
  
  <pre><code>1. add text1, text2, ... to an array (I don't know how to get each string and get rid of the comma "'")
  2. suppose we have 
  
      string[] stringArray = { "text1", "text2", "text3", "text4", "text6", ... };
  </code></pre>
  
  <p>we can check the frequency by:</p>
  
  <pre><code>foreach (string x in stringArray)
  {
      if (x.Contains(stringToCheck))
      {
          // increase the number of count
      }
  }
  </code></pre>
  
  <p>3. I don't know how to stick that count number to each skill then later we can display it.
  I am thinking of something like Map map  = new HashMap();</p>