How to convert single char to double
<p>I try to create a program that can evaluate simple math expression like "4+4". The expression is given from the user. </p>

<p>The program saves it in a <code>char*</code> and then searches for binary operation (+,-,*,:) and does the operation. </p>

<p>The problem is that I can't figure out how to convert the <strong>single</strong> <code>char</code> into a <code>double</code> value. </p>

<p>I know there is the <code>atof</code> function but I want to convert single <code>char</code>.</p>

<p>There is a way to do that without creating a <code>char*</code>?</p>