CloudFormation's Fn::CIDR returns a list of CIDR blocks and not a string. So we need to use a listified token instead of a string. #2671 eladb mentioned this issue May 29, 2019 fix (cdk): Fn.cidr ...

return palindromeCheck (s.substring(1, s.length()-1)); } return false; } /* End of Java String palindrome checker method */ } /* End of Java palindrome program */ Example Java palindrome checker ...