Question

我将代码输入到列表中。但是，当我尝试在方法调用中迭代代码时，没有返回任何内容。

问题代码可以在＆＃34;公共类迭代＆＃34;中找到。我不确定为什么它不会执行。

基本上，我希望有人输入信息。输入信息后，我希望用户通过方法调用遍历列表。

 using System;
 using System.Text.RegularExpressions;
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;


public class Iterating
{
    List<String> employees = new List<String>();

    public void Test2()
    {
        //This is where I am trying to iterate//
        for (int i = 0; i < employees.Count; i++)
        {
            Console.WriteLine(employees[i]);
        }
    }
}

public class Testing
{
    public void Test1()
    {
        while (true)
        {
            List<String> employees = new List<String>();

            Regex regex = new Regex(@"((.{5})-\d{2,5}-\d{2,5})|(@.*.com)");
            Console.WriteLine("Please enter an e-mail");
            string input = Console.ReadLine();

            if(string.Equals(input, "quit", StringComparison.OrdinalIgnoreCase)) 
            {
                Console.WriteLine("You have quit the program");
                break;
            }
            else if (match.Success)
            {
                Console.WriteLine(match.Value);
                employees.Add(match.Value);
            }
        }
    }
}

public class Program
{
    public static void Main()
    {
        Testing T1 = new Testing();
        T1.Test1();
        Iterating I1 = new Iterating();
        I1.Test2();
    }
}

Answer 1

自

以来你没有得到任何输出

集合阶段中的每个循环都使用新的employees列表。
您的两个班级不共享相同的employees列表 - 每个班级都有自己独立的列表如果希望迭代类打印列表的内容，则需要将其传递给相关列表。

部分示例：

public class Program {
    public static void Main() {
        List<String> employees = new List<String>();
        Testing T1 = new Testing();
        T1.Test1(employees);
        Iterating I1 = new Iterating();
        I1.Test2(employees);
    }
}

您可以修改测试方法以使用传递的列表而不是创建新的

Answer 2

  public class Iterating {
    List<String> employees = new List<String>();

    public void Test2()
    {
        //This is where I am trying to iterate//
        for (int i = 0; i < employees.Count; i++)
        {
            Console.WriteLine(employees[i]);
        }
    } 
   }

员工总是空着的，因为这与Testing.employees没有任何关系，你可能想要删除它并将列表传递给Test2或构造函数。

此外，Testing.employees应该在外面看

你可以像这样重新设计你的课程

public class Iterating
{    
    public void Test2(List<String> employees)
    {
        //This is where I am trying to iterate//
        for (int i = 0; i < employees.Count; i++)
        {
            Console.WriteLine(employees[i]);
        }
    }
}

public class Testing
{
    public List<String> Test1()
    {
        List<String> employees = new List<String>();//this should be outside the while loop
        while (true)
        {    
            Regex regex = new Regex(@"((.{5})-\d{2,5}-\d{2,5})|(@.*.com)");
            Console.WriteLine("Please enter an e-mail");
            string input = Console.ReadLine();

            if(string.Equals(input, "quit", StringComparison.OrdinalIgnoreCase)) 
            {
                Console.WriteLine("You have quit the program");
                break;
            }
            else if (match.Success)
            {
                Console.WriteLine(match.Value);//where is the match var
                employees.Add(match.Value);//where is the match var
            }
        }

        return employees;
    }
}

public class Program
{
    public static void Main()
    {
        Testing T1 = new Testing();
        var employees = T1.Test1();
        Iterating I1 = new Iterating();
        I1.Test2(employees);
    }
}

通过方法调用

2 个答案: