public class test {

        public static void main(String args[]) {
            //overflow, because assign an integer to charcter.
            char a=1;
            char b=9;
            System.out.println(a);
            System.out.println(b);

            //correct assign
            char c='1';
            char d='9';
            System.out.println(c);
            System.out.println(d+"\n");

            //correct assign,
            //and treat as a decimal number when being
            //in the run time, this decimal number is
            //defined in the ASCII table
            char e='1';
            char f='9';
            System.out.println((int)e);
            System.out.println((int)f);
        }
}