Проблема с кодом с использованием массивов

Question

Он собирается без проблем, но когда я вставляю фразу, в общем окне вывода выдается следующая ошибка:

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 2
    at java.lang.String.charAt(String.java:686)
    at encoder.main(encoder.java:77)

Process completed.

Может кто-нибудь сказать мне, в чем проблема и как ее исправить??

Вот код:

/**
 * @(#)encoder.java
 *
 *
 * @author Armando Herrera
 * @version Alpha Encoder 0.1 2011/4/9
 */
import javax.swing.*;
import java.lang.*;
import java.util.*;

public class encoder {

    /**
     * Creates a new instance of <code>encoder</code>.
     */
    public encoder() {
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        String strencodersequense = JOptionPane.showInputDialog("Input a 9 digit number");///ask for sequenser///
        int digitlength = strencodersequense.length();
        if(digitlength != 9)
        {
            JOptionPane.showMessageDialog(null, "The number you entered is not desired lenght.");/////check if they put number of digits
            System.exit(0);
        }
        ///////////////////////////split the codersequense into char parts/////////////////////////////
        char firstdigitchar = strencodersequense.charAt(0);
        char seconddigitchar = strencodersequense.charAt(1);
        char thirddigitchar = strencodersequense.charAt(2);
        char fourthdigitchar = strencodersequense.charAt(3);
        char fifthdigitchar = strencodersequense.charAt(4);
        char sixthdigitchar = strencodersequense.charAt(5);
        char seventhdigitchar = strencodersequense.charAt(6);
        char eightdigitchar = strencodersequense.charAt(7);
        char ninthdigitchar = strencodersequense.charAt(8);
        //////////////////////////change split chars to strings///////////////////////////////////////
        String firstdigitstr = Character.toString(firstdigitchar);
        String seconddigitstr = Character.toString(seconddigitchar);
        String thirddigitstr = Character.toString(thirddigitchar);
        String fourthdigitstr = Character.toString(fourthdigitchar);
        String fifthdigitstr = Character.toString(fifthdigitchar);
        String sixthdigitstr = Character.toString(sixthdigitchar);
        String seventhdigitstr = Character.toString(seventhdigitchar);
        String eightdigitstr = Character.toString(eightdigitchar);
        String ninthdigitstr = Character.toString(ninthdigitchar);
        //////////////////////////change split strings into integers///////////////////////////////////////
        int firstdigitint = Integer.parseInt(firstdigitstr);
        int seconddigitint = Integer.parseInt(seconddigitstr);
        int thirddigitint = Integer.parseInt(thirddigitstr);
        int fourthdigitint = Integer.parseInt(fourthdigitstr);
        int fifthdigitint = Integer.parseInt(fifthdigitstr);
        int sixthdigitint = Integer.parseInt(sixthdigitstr);
        int seventhdigitint = Integer.parseInt(seventhdigitstr);
        int eightdigitint = Integer.parseInt(eightdigitstr);
        int ninthdigitint = Integer.parseInt(ninthdigitstr);
        /////////////////////////////////finished processing sequense//////////////////////////////////////
        String toencode = JOptionPane.showInputDialog("Input phrase to encode, with no special characters and in lower caps" + 
                                                        " Note: it will not work with special characters.");//////asked phrase/////
        int toencodelenght = toencode.length();///get phrase lenght
        int passcode = firstdigitint * seconddigitint * thirddigitint * fourthdigitint * fifthdigitint *
                       sixthdigitint * seconddigitint * eightdigitint * ninthdigitint; ////make a combination of the digits////
        ////////////////////////////turn string into numbers////////////////////////////////////////////////////////////////////////////////////////

        int i = 0;

        char[] toencodecharacter = new char[toencodelenght];///start (making arrays)
        String[] toencodestringchar = new String[toencodelenght];
        int[] beforeencodenumber = new int[toencodelenght];
        int[] afterencodenumber = new int[toencodelenght];

        while(i <= toencodelenght)
            {
            toencodecharacter[i] = toencode.charAt(i); //////split characters//////
            toencodestringchar[i] = Character.toString(toencodecharacter[i]);
            if(toencodestringchar[i].equals("a")) //process the characters individually
                {
                    beforeencodenumber[i] = 1;
                }
            if(toencodestringchar[i].equals("b"))
                {
                    beforeencodenumber[i] = 2;
                }
            if(toencodestringchar[i].equals("c"))
                {
                    beforeencodenumber[i] = 3;
                }
            if(toencodestringchar[i].equals("d"))
                {
                    beforeencodenumber[i] = 4;
                }
            if(toencodestringchar[i].equals("e"))
                {
                    beforeencodenumber[i] = 5;
                }
            if(toencodestringchar[i].equals("f"))
                {
                    beforeencodenumber[i] = 6;
                }
            if(toencodestringchar[i].equals("g"))
                {
                    beforeencodenumber[i] = 7;
                }
            if(toencodestringchar[i].equals("h"))
                {
                    beforeencodenumber[i] = 8;
                }
            if(toencodestringchar[i].equals("i"))
                {
                    beforeencodenumber[i] = 9;
                }
            if(toencodestringchar[i].equals("j"))
                {
                    beforeencodenumber[i] = 10;
                }
            if(toencodestringchar[i].equals("k"))
                {
                    beforeencodenumber[i] = 11;
                }
            if(toencodestringchar[i].equals("l"))
                {
                    beforeencodenumber[i] = 12;
                }
            if(toencodestringchar[i].equals("m"))
                {
                    beforeencodenumber[i] = 13;
                }
            if(toencodestringchar[i].equals("n"))
                {
                    beforeencodenumber[i] = 14;
                }
            if(toencodestringchar[i].equals("o"))
                {
                    beforeencodenumber[i] = 15;
                }
            if(toencodestringchar[i].equals("p"))
                {
                    beforeencodenumber[i] = 16;
                }
            if(toencodestringchar[i].equals("q"))
                {
                    beforeencodenumber[i] = 17;
                }
            if(toencodestringchar[i].equals("r"))
                {
                    beforeencodenumber[i] = 18;
                }
            if(toencodestringchar[i].equals("s"))
                {
                    beforeencodenumber[i] = 19;
                }
            if(toencodestringchar[i].equals("t"))
                {
                    beforeencodenumber[i] = 20;
                }
            if(toencodestringchar[i].equals("u"))
                {
                    beforeencodenumber[i] = 21;
                }
            if(toencodestringchar[i].equals("v"))
                {
                    beforeencodenumber[i] = 22;
                }
            if(toencodestringchar[i].equals("w"))
                {
                    beforeencodenumber[i] = 23;
                }
            if(toencodestringchar[i].equals("x"))
                {
                    beforeencodenumber[i] = 24;
                }
            if(toencodestringchar[i].equals("y"))
                {
                    beforeencodenumber[i] = 25;
                }
            if(toencodestringchar[i].equals("z"))
                {
                    beforeencodenumber[i] = 26;
                }
            if(toencodestringchar[i].equals(" "))
                {
                    beforeencodenumber[i] = 27;
                }
            if(toencodestringchar[i].equals("1"))
                {
                    beforeencodenumber[i] = 28;
                }
            if(toencodestringchar[i].equals("2"))
                {
                    beforeencodenumber[i] = 29;
                }
            if(toencodestringchar[i].equals("3"))
                {
                    beforeencodenumber[i] = 30;
                }
            if(toencodestringchar[i].equals("4"))
                {
                    beforeencodenumber[i] = 31;
                }
            if(toencodestringchar[i].equals("5"))
                {
                    beforeencodenumber[i] = 32;
                }
            if(toencodestringchar[i].equals("6"))
                {
                    beforeencodenumber[i] = 33;
                }
            if(toencodestringchar[i].equals("7"))
                {
                    beforeencodenumber[i] = 34;
                }
            if(toencodestringchar[i].equals("8"))
                {
                    beforeencodenumber[i] = 35;
                }
            if(toencodestringchar[i].equals("9"))
                {
                    beforeencodenumber[i] = 36;
                }
            if(toencodestringchar[i].equals("0"))
                {
                    beforeencodenumber[i] = 37;
                }
            afterencodenumber[i] = beforeencodenumber[i] * passcode;
            if(i == toencodelenght)
                {
                    String numbers = "encoded with :" + strencodersequense + ": the encoded text is :" + Arrays.toString(afterencodenumber);
                    JOptionPane.showConfirmDialog(null, numbers);
                }
            i = i + 1;
            }

        }
    }

Answer 1

Попробуйте изменить цикл while на <, а не <=.Когда вы просматриваете массив размером length, вы всегда хотите использовать <, потому что массивы индексируются 0.Если у вас 9 элементов, последний элемент имеет индекс 8 и если вы используете <= в цикле, вы в конечном итоге попытаетесь найти значение индекса 9, которое выходит за пределы.

Answer 2

В этом случае это String, а не Array, но применяется та же логика. Индекс в cahrAt может варьироваться от 0 до, но , не включая длину строки.

Еще один комментарий: более 30 выражений if ужасны. Я уверен, что есть простой алгоритм, который отображает эти буквы на цифры. Иногда 5 минут размышлений экономят вам 1/2 часа печати. ​​