java - 如何使用 String.equals 和 String.compareTo 按字母顺序对用户输入的字符串名称进行排序

Question

该程序的输出应该是:

Enter first : Alexis
Enter Second : Zach
Enter Third : Cassie

Here are sorted the sorted name:

Alexis

Cassie

Zach

但如果名称相同，则必须输出一条错误消息，说明名称相同。

示例输入姓名 1 亚历克西斯输入姓名 2 亚历克西斯输入姓名 3 凯蒂

名称一和名称二相同。

import java.util.Scanner;
import java.util.Arrays;


public class AlexisPriceAssignment6
{
        public static String input = " ";
        public static String input2 = " ";
        public static String input3 = "";


    public static void Greet()
    {
        System.out.println("Welcome to Alexis Price's Name Sorter.");
        System.out.println("All names must be unique.");

    }
    public static void Uinput()
    {
          Scanner keyboard = new Scanner(System.in);

        System.out.print("Enter the first name: ");
        input = keyboard.nextLine();
        char one = input.charAt(0);

        System.out.print("Enter the second name: ");
        input2 = keyboard.nextLine();
        char two = input2.charAt(0);

        System.out.print("Enter the third name: " );
        input3 = keyboard.nextLine();
        char three = input3.charAt(0);

        System.out.println();
        if (input.equals(input2) )
        {
            System.out.println(input + " is the same as "+ input2);
        }
        if ( input.equals(input3))
        {
           System.out.println(input + " is the same as "+ input3);
        }
        if (input2.equals(input3))
        {
            System.out.println(input2 + " is the same as "+ input3);
        }
        if (input!=(input2))
        {
            sort();
        }


    }

    public static void sort()
    {
        System.out.println("Here are the sorted names.");

        char charArray [] = input.toCharArray();
        Arrays.sort(charArray);
        String sortedString = new String(charArray);
        System.out.println(sortedString);


    }


    public static void main(String[] args)
    {
        Greet();
        Uinput();


    }

}

Answer 1

检查:

    if (input!=(input2))
    {
        sort();
    }

都是错误的，因为 String 使用 .equals() 方法进行比较，并且没有用，因为您已经通过直接比较每对来检查所有三个组合。只需在 3 个 if 语句之后调用 sort() 方法即可。