How to extract unique characters from a string?
<p>How to extract unique characters from a string using c#? </p>

<p>For example:</p>

<p>I have string "aabbcccddeefddg" and I want to extract unique charecters from the string, the result set should be "abcdefg". </p>

<p><strong>Note</strong>: I don't want to use string.distinct function in c#.</p>

<p>Thanks,</p>

<p>Pradeep</p>
