C# Regular expressions, get left and right words separated by a comma
<p>I have following input string
string <code>str = "a,b,c,d";</code></p>

<p>Output expected in groups, like (get the left and right word of each comma)</p>

<pre><code>[group0 : a b]       [group1 : b c]       [group2 : c d]
</code></pre>
