java - 如何计算数组中字符串值中的字符数，然后将其与其他字符进行比较以找到最长的字符？

Question

以下是我现在所拥有的。我只需要知道的主要事情是如何检查数组中字符串的字符数，然后将其与所有其他条目进行检查并仅提取最大的条目。我正在处理的问题是：

编写一个程序，从用户那里读取姓名和出生年份，直到输入一个空行。姓名和出生年份用逗号隔开。

之后，程序会打印最长的姓名和出生年份的平均值。如果多个名称的长度相同，则可以打印其中任何一个。您可以假设用户至少输入了一个人。样本输出

塞巴斯蒂安，2017 卢卡斯，2017 莉莉，2017 汉娜，2014 加布里埃尔，2009

最长的名字：塞巴斯蒂安平均出生年数：2014.8

import java.util.Scanner;
public class Test112 {

    //Asks the user for input and will print out who is the oldest


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

        int checkVal = 0;
        String checkName = null;

        System.out.println("Provide a name and age in this format: name,#");

        while (true) {

            //The unique thing about this code, is each input is a separate array that is not put in memory
            //You just use the array system to pull data of the values entered at that specific time
            String userIn = scanner.nextLine();

            if (userIn.equals("")) {
                break;
            } 

            //Here we get the info from the user, then split it
            String[] valArray = userIn.split(",");

            //This now uses the variable to check which value of arguments entered is the greatest
            //It'll then assign that value to the variable we created
            **if (checkVal < Integer.valueOf((int)valArray[0].length) {**
                //We need the checkVal variable to be a constant comparison against new entries
                checkVal = Integer.valueOf(valArray[1]);
                //This pulls the name of the value that satisfies the argument above
                checkName = valArray[0];
            }
        }

        System.out.println("Name of the oldest: " + checkName);
    scanner.close();

    }
}

标签： javaarraysstring

Answer 1

如何计算数组中字符串值中的字符数，然后将其与其他字符进行比较以找到最长的字符？

执行以下操作：

if (checkVal < valArray[0].length()) {
    checkVal = valArray[0].length();
    checkName = valArray[0];
}

请注意，length()用于查找 a 的长度String。

其他一些重要的点：

1. 您还需要一个变量来存储所有出生年份的总和，以便计算它们的平均值。或者，您可以计算运行平均值。
2. 在对条目执行任何操作之前修剪条目（姓名和出生年份）。
3. 不要关闭Scannerfor System.in。

下面给出了包含注释的完整程序：

import java.util.Scanner;

public class Main {

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

        int checkVal = 0;
        String checkName = "", name, birthYearStr;
        int sum = 0, count = 0;

        while (true) {
            System.out.print("Provide a name and age in this format: name,#");
            String userIn = scanner.nextLine();

            if (userIn.equals("")) {
                break;
            }
            String[] valArray = userIn.split(",");
            name = valArray[0].trim();
            birthYearStr = valArray[1].trim();
            if (valArray.length == 2 && birthYearStr.length() == 4) { // Birth year should be of length 4
                try {
                    sum += Integer.parseInt(birthYearStr);
                    if (checkVal < name.length()) {
                        checkVal = name.length();
                        checkName = name;
                    }
                    count++;
                } catch (NumberFormatException e) {
                    System.out.println("Birth year should be an integer. Please try again.");
                }
            } else {
                System.out.println("This is an invalid entry. Please try again.");
            }
        }

        System.out.println("Longest name: " + checkName);
        System.out.println("Average of birth years: " + (sum / count));
    }
}

示例运行：

Provide a name and age in this format: name,#sebastian,2017
Provide a name and age in this format: name,#lucas,2017
Provide a name and age in this format: name,#lily,2017
Provide a name and age in this format: name,#hanna,2014
Provide a name and age in this format: name,#gabriel,2009
Provide a name and age in this format: name,#
Longest name: sebastian
Average of birth years: 2014

另一个示例运行：

Provide a name and age in this format: name,#sebastian,201
This is an invalid entry. Please try again.
Provide a name and age in this format: name,#sebastian,hello
This is an invalid entry. Please try again.
Provide a name and age in this format: name,#sebastian,2017
Provide a name and age in this format: name,#lucas,2017
Provide a name and age in this format: name,#lily,2017
Provide a name and age in this format: name,#hanna,2014
Provide a name and age in this format: name,#gabriel,2009
Provide a name and age in this format: name,#
Longest name: sebastian
Average of birth years: 2014

另一个示例运行：

Provide a name and age in this format: name,#hello,2018,sebastian,2017
This is an invalid entry. Please try again.
Provide a name and age in this format: name,#hello,2018
Provide a name and age in this format: name,#sebastian,2017
Provide a name and age in this format: name,#
Longest name: sebastian
Average of birth years: 2017

另一个示例运行：

Provide a name and age in this format: name,#sebastian,rama
Birth year should be an integer. Please try again.
Provide a name and age in this format: name,#sebastian,12.5
Birth year should be an integer. Please try again.
Provide a name and age in this format: name,#sebastian,2017
Provide a name and age in this format: name,#abcdefghi,2018
Provide a name and age in this format: name,#rama,2009
Provide a name and age in this format: name,#
Longest name: sebastian
Average of birth years: 2014

另一个示例运行：

Provide a name and age in this format: name,#sebastian,2017
Provide a name and age in this format: name,#lucas,2017
Provide a name and age in this format: name,#lily   ,          2017
Provide a name and age in this format: name,#
Longest name: sebastian
Average of birth years: 2017