Question

所以，今天，我接受了一个学校项目，我真的需要帮助。

我需要找到这个数组中每个元素的第一个和最后一个字母，然后打印出来。对于你们所有的java人，你能告诉我为了做到这一点我需要什么样的函数，方法或代码吗？

当我编译并运行它时出现的问题之一是它所说的charAt（a）;它告诉我它无法承担那里的角色，无论出于何种原因。

所以，如果你可以帮助我解决这个问题，我将不胜感激，因为这是今晚到期的，我无法理解。

非常感谢。

/**
 * Write a description of class Pokemon here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */

import java.util.Scanner;

public class Pokemon
{
public static void main (String [ ] args)
{
    Scanner scan = new Scanner(System.in);

    String array [ ] = new String [ 10 ];

    array [ 0 ] = "Charizard";
    array [ 1 ] = "Pikachu";
    array [ 2 ] = "Jigglypuff";
    array [ 3 ] = "Timburr";
    array [ 4 ] = "Conkeldurr";
    array [ 5 ] = "Gurdurr";


    System.out.println("------------------------========================------------------------");
    System.out.println(" ");
    System.out.println("                 .\"-,.__");
    System.out.println("                 `.     `.  ,");
    System.out.println("            .--'  .._,'\"-' `.");
    System.out.println("             .    .'         `'");
    System.out.println("             `.   /          ,'");
    System.out.println("               `  '--.   ,-\"'");
    System.out.println("                `\"`   |  \\");
    System.out.println("                   -. \\, |");
    System.out.println("                    `--Y.'      ___.");
    System.out.println("                         \\     L._, \\");
    System.out.println("               _.,        `.   <  <\\                _");
    System.out.println("             ,' '           `, `.   | \\            ( `");
    System.out.println("          ../, `.            `  |    .\\`.           \\ \\_");
    System.out.println("         ,' ,..  .           _.,'    ||\\l            )  '\".");
    System.out.println("        , ,'   \\           ,'.-.`-._,'  |           .  _._`.");
    System.out.println("      ,' /      \\ \\        `' ' `--/   | \\          / /   ..\\");
    System.out.println("    .'  /        \\ .         |\\__ - _ ,'` `        / /     `.`.");
    System.out.println("    |  '          ..         `-...-\"  |  `-'      / /        . `.");
    System.out.println("    | /           |L__           |    |          / /          `. `.");
    System.out.println("   , /            .   .          |    |         / /             ` `");
    System.out.println("  / /          ,. ,`._ `-_       |    |  _   ,-' /               ` \\");
    System.out.println(" / .           \"`_/. `-_ \\_,.  ,'    +-' `-'  _,        ..,-.    \\`.");
    System.out.println("  '         .-f    ,'   `    '.       \\__.---'     _   .'   '     \\ \\");
    System.out.println("' /          `.'    l     .' /          \\..      ,_|/   `.  ,'`     L`");
    System.out.println("|'      _.-\"\"` `.    \\ _,'  `            \\ `.___`.'\"`-.  , |   |    | \\");
    System.out.println("||    ,'      `. `.   '       _,...._        `  |    `/ '  |   '     .|");
    System.out.println("||  ,'          `. ;.,.---' ,'       `.   `.. `-'  .-' /_ .'    ;_   ||");
    System.out.println("|| '              V      / /           `   | `   ,'   ,' '.    !  `. ||");
    System.out.println("||/            _,-------7 '              . |  `-'    l         /    `||");
    System.out.println(" |          ,' .-   ,' ||               | .-.        `.      .'     ||");
    System.out.println(" `'        ,'    `\".'    |               |    `.        '. -.'       `'");
    System.out.println("          /      ,'      |               |,'    \\-.._,.'/'");
    System.out.println("          .     /        .               .       \\    .''");
    System.out.println("        .`.    |         `.             /         :_,'.'");
    System.out.println("          \\ `...\\   _     ,'-.        .'         /_.-'");
    System.out.println("           `-.__ `,  `'   .  _.>----''.  _  __  /");
    System.out.println("                .'        /\"'          |  \"'   '_");
    System.out.println("               /_|.-'\\ ,\\\".             '.'`__'-( \\");
    System.out.println("                 / ,\\\"'\\\"\\,'               `/  `-.|\"");
    System.out.println(" ");
    System.out.println("------------------------========Charizard========------------------------");

    System.out.println(" ");
    System.out.println(" ");        
    System.out.println("Items in array:  ");
    System.out.println(" ");
    System.out.println("0 - " + array [ 0 ]);
    System.out.println("1 - " + array [ 1 ]);
    System.out.println("2 - " + array [ 2 ]);
    System.out.println("3 - " + array [ 3 ]);
    System.out.println("4 - " + array [ 4 ]);
    System.out.println("5 - " + array [ 5 ]);
    System.out.println(" ");
    System.out.println(" ");

    int a = (array [ 0 ]).length();
    int b = (array [ 1 ]).length();
    int c = (array [ 2 ]).length();
    int d = (array [ 3 ]).length();
    int e = (array [ 4 ]).length();
    int f = (array [ 5 ]).length();


    char g = (array [ 0 ]).charAt(0);
    char h = (array [ 1 ]).charAt(0);
    char i = (array [ 2 ]).charAt(0);
    char j = (array [ 3 ]).charAt(0);
    char k = (array [ 4 ]).charAt(0);
    char l = (array [ 5 ]).charAt(0);

    char m = (array [ 0 ]).charAt(a);
    char n = (array [ 1 ]).charAt(b);
    char o = (array [ 2 ]).charAt(c);
    char p = (array [ 3 ]).charAt(d);
    char q = (array [ 4 ]).charAt(e);
    char r = (array [ 5 ]).charAt(f);

    System.out.println(array [ 0 ] + "  -  First letter of element: " + g + "    Second letter of element: " + m);
    System.out.println(array [ 1 ] + "  -  First letter of element: " + h + "    Second letter of element: " + n);
    System.out.println(array [ 2 ] + "  -  First letter of element: " + i + "    Second letter of element: " + o);
    System.out.println(array [ 3 ] + "  -  First letter of element: " + j + "    Second letter of element: " + p);
    System.out.println(array [ 4 ] + "  -  First letter of element: " + k + "    Second letter of element: " + q);
    System.out.println(array [ 5 ] + "  -  First letter of element: " + l + "    Second letter of element: " + r);
}

}

Answer 1

你必须使用，

    char m = (array [ 0 ]).charAt(a-1);
    char n = (array [ 1 ]).charAt(b-1);
    char o = (array [ 2 ]).charAt(c-1);
    char p = (array [ 3 ]).charAt(d-1);
    char q = (array [ 4 ]).charAt(e-1);
    char r = (array [ 5 ]).charAt(f-1);

因为索引从0开始，而最后一个字母的索引是（length-1）

但最好为此

使用for循环

for(int v=0;v<6;v++){
    System.out.println(array [ v ] + "  -  First letter of element: " + array[v].charAt(0) + "    Second letter of element: " + array[v].charAt(array[v].length()-1));
}

Answer 2

基于零的索引

char m = (array [ 0 ]).charAt(a-1);

Answer 3

这可以帮到你：

public class CalculateActionListener {

    //Here's the actual ActionListener
    private ActionListener calculateListener = new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            JOptionPane.showMessageDialog(null, "WORKING!");
        }
    };

    //Getter for my ActionListener
    public ActionListener getCalculateListener() {
        return calculateListener;
    }
}

我需要一个数组元素的长度，然后打印最后一个字符

3 个答案: