Changing the likes of ' azz ' and ' daz ' to ' baa ' and ' dba ' respectively
while ( index >= 0 && t [ index ] == ' z ' ) { t = t . Substring ( 0 , index ) + ' a ' + t . Substring ( index + 1 ) ; index -- ; } if ( index >= 0 ) { t = t . Substring ( 0 , index ) + Convert . ToChar ( ( int ) t [ index ] + 1 ) + t . Substring ( index + 1 ) ; }