changeLetter method
:QUEST: ?? Make it better with regExp? Change letter/s in a String
Implementation
String changeLetter(String inS, int pos, String newS) {
//print(inS);
int length = inS.length;
String _s1 = inS.substring(0, pos - 1);
//print(_s1);
String _s2 = inS.substring(pos, pos + 1); // wanted OLD letter for change
_s2 = newS; // Now it is changed
//print(_s2);
String _s3 = inS.substring(pos, length);
//print(_s3);
String s4 = '$_s1$_s2$_s3';
//print(s4);
return s4;
}