How can I change an user input char eg. "abcDEF" and return an output "222333"
<p>How can I change an user input char eg. "abcDEF"
and return an output "222333" without using atoi or stringstream</p>

<p>using the traditional SMS idea where 
2 is equal to abc
3 is equal to def
4 is equal to ghi
etc.</p>
