Question

所以我在编程方面很糟糕，我必须为大学课程做这件事，并且不能理解一些概念。这就是我对此的看法。我究竟做错了什么？如何调用这些方法将主要消息返回给main？检查方法是从另一个站点借来填补空白，而我试图找出验证回文的字符串缓冲方法。很多评论都是尚未完成的进展。如果这太混乱了，请告诉我，我会重新开始。谢谢。

import java.util.*;
import java.lang.StringBuffer;

public class palindrome {
    public static void main(String[] args) {

    }

    public static String retrieveInput(String number) {
        Scanner input = new Scanner(System.in);

        System.out.print("Enter a 5 digit integer: ");
        number = input.toString();

        while (number.length() != 5) {
            System.out.println("ERROR!!!  Integer must be 5 digits. Please enter a 5 digit integer: ");
            System.out.print("Enter a 5 digit integer: ");
            number = input.toString();
        }
        if (number.matches("[0-9]+")) {

        } else {
            System.out.println("ERROR!!! Input must be numeric. Please enter a 5 digit integer: ");
            System.out.print("Enter a 5 digit integer: ");
            number = input.toString();
        }
        return number;
    } 

    // Change, TESTING ONLY!!!!!!!
    public static String check(String number) {
        String original = number;
        String reverse = "";

        int length = original.length();

        for ( int i = length - 1; i >= 0; i-- )
            reverse = reverse + original.charAt(i);

        if (original.equals(reverse))
            System.out.println("Entered string is a palindrome.");
        else
            System.out.println("Entered string is not a palindrome.");

        return number;
        //StringBuffer Palindrome = new StringBuffer(number);
        //return number.equals(reverseString);
    }

    //StringBuffer original = new StringBuffer();
    //  StringBuffer reverse = original.reverse();  
    //  if (original != original.reverse()) {
    //  System.out.print("This is not a palindrome");
    //}
    //return number;

    public static String display(String number) {
        return number + " is a valid palindrome!";
    }
}

Answer 1

试试这个（经过微小修改后修改）

import java.util.Scanner;

public class Palindrome { // Prefer beginning class name with a capital letter
                          // (Java naming convention)

    public static void main(String[] args) {

    }

    public static String retrieveInput(String number) {
        Scanner input = new Scanner(System.in);

        System.out.print("Enter a 5 digit integer: ");
        number = input.nextLine(); // Replace this

        while (number.length() != 5) {
            System.out
                    .println("ERROR!!!  Integer must be 5 digits. Please enter a 5 digit integer: ");
            System.out.print("Enter a 5 digit integer: ");
            number = input.nextLine(); // Replace this
        }
        if (number.matches("[0-9]+")) {

        } else {
            System.out.println("ERROR!!! Input must be numeric. Please enter a 5 digit integer: ");
            System.out.print("Enter a 5 digit integer: ");
            number = input.nextLine(); // Replace this
        }

        input.close(); // Close your scanner after you are done using it.

        return number;
    }

    // Change, TESTING ONLY!!!!!!!
    public static String check(String number) {
        String original = number;
        String reverse = "";

        int length = original.length();

        for (int i = length - 1; i >= 0; i--)
            reverse = reverse + original.charAt(i);

        if (original.equals(reverse))
            System.out.println("Entered string is a palindrome.");
        else
            System.out.println("Entered string is not a palindrome.");

        return number;
        // StringBuffer Palindrome = new StringBuffer(number);
        // return number.equals(reverseString);
    }

    // StringBuffer original = new StringBuffer();
    // StringBuffer reverse = original.reverse();
    // if (original != original.reverse()) {
    // System.out.print("This is not a palindrome");
    // }
    // return number;

    public static String display(String number) {
        return number + " is a valid palindrome!";
    }
}

创建回文的方法

1 个答案: