Ví dụ về String method trong Java: charAt()

            public char charAt(int index)
        

            public class charAtMethod {
    public static void main(String args[]) {
        String s1 = "This is String CharAt Method";
        //returns the char value at the 0 index
        System.out.println("Character at 0 position is: " + s1.charAt(0));
        //returns the char value at the 5th index
        System.out.println("Character at 5th position is: " + s1.charAt(5));
        //returns the char value at the 22nd index
        System.out.println("Character at 22nd position is: " + s1.charAt(22));
        //returns the char value at the 23th index
        char result = s1.charAt(-1);
        System.out.println("Character at 23th position is: " + result);
    }
}
        

            Character at 0 position is: T
Character at 5th position is: i
Character at 22nd position is: M
        

            Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: -1