Flutter - Dart - remove hidden character from String input - list

Question

I'm trying to compare 2 strings, however my comparison always fails.
For reference, the one string is a filename I'm getting from the phones storage and it look like it ends with an apostrophe, although its not visible anywhere.
Please consider the following dart code:
import 'dart:convert';
void main() {
const Utf8Codec utf8 = Utf8Codec();
String input = 'chatnum.txt';
String stringwithapostrophe = 'chatnum.txt\'';
String compInput = utf8.encode(input).toString();
String compComp = utf8.encode(stringwithapostrophe).toString();
print (compInput);
print (compComp);
if (compInput == compComp) {
print ('Yes it matches');
} else {
print ('No it does not');
}
}
This output's a result of:
[99, 104, 97, 116, 110, 117, 109, 46, 116, 120, 116]
[99, 104, 97, 116, 110, 117, 109, 46, 116, 120, 116, 39]
No it does not
So how can I remove that last apostrophe from the String?
I've tried .removeAt and .removeLast. But I just can't crack this.

Answer 1

I applied regex to it. That sorted it:
String filenametosend = (basename(f.toString()))
.replaceAll(RegExp(r"[-!$%^&*()+|~=`{}##\[\]:;'’<>?,\/"
'"”'
"]"), '');

Answer 2

This way too:
final apostrophe = '\'';
final length = stringwithapostrophe.length;
if (length > 0 && stringwithapostrophe[length - 1] == apostrophe) {
stringwithapostrophe = stringwithapostrophe.substring(0, length - 1);
}
Or this way (remove all):
final apostrophe = '\'';
stringwithapostrophe = stringwithapostrophe.replaceAll(apostrophe, '');
Remove (any) last:
final length = stringwithapostrophe.length;
stringwithapostrophe = length > 0
? stringwithapostrophe.substring(0, length - 1)
: stringwithapostrophe;