title: C# List<Dictionary<string,string>> - how to extract unique key/value pairs
body: <p>In a C# List>, how can I extract unique key/value pairs and store it in List>?</p>
  
  <pre><code>List&lt;Dictionary&lt;string,string&gt;&gt; md = new List&lt;Dictionary&lt;string,string&gt;&gt;();
  </code></pre>
  
  <h2>Input</h2>
  
  <p>md[0] :</p>
  
  <pre><code>[0]:"A","Apple"
  [1]:"B","Ball"
  </code></pre>
  
  <p>md[1]: </p>
  
  <pre><code>[0]:"A","Apple"
  [1]:"B","Ball"
  </code></pre>
  
  <p>md[2]:</p>
  
  <pre><code>[0]: "C", "Cat"
  [1]: "D", "Dog"
  </code></pre>
  
  <h2>Output</h2>
  
  <p>md[0] :</p>
  
  <pre><code>[0]:"A","Apple"
  [1]:"B","Ball"
  </code></pre>
  
  <p>md[1]:</p>
  
  <pre><code>[0]:"C" : "Cat"
  [1]:"D" : "Dog"
  </code></pre>
  
  <p>Code sample to extract both unique key/value pairs are needed, only unique keys or unique values are not needed.</p>
  
  <p>(* Note : [0],[1] above depicts the indexes in the list and dictionary and not the keys or values)</p>