克服每个循环的无效错误

Question

下面是我正在处理的代码的一部分，执行时出现以下错误。'不能将类型 void 隐式转换为字符串'。我该如何解决？private static void Main(string[] args){    string[] strArray = new string[n];    int i = 0;    foreach (example)    {        if (condition 1)        {            strArray[i] = output;        }        if (condition 2)        {            strArray[i] = output;        }        if (condition 3)        {            strArray[i] = output;        }        i = i + 1;    }}

Answer 1

当我向你展示代码时

private static void Main(string[] args)

{

    string[] strArray = new string[n];

    int i = 0;

    foreach (example)

    {

        if (condition 1)

        {

            strArray[i] = output;

        }

        if (condition 2)

        {

            strArray[i] = output;

        }

        if (condition 3)

        {

            strArray[i] = output;

        }

        i = i + 1;

    }

}

进入 .net 小提琴，我得到：

Compilation error (line 1, col 16): Expected class, delegate, enum, interface, or struct

Compilation error (line 1, col 33): Identifier expected

Compilation error (line 1, col 35): Expected class, delegate, enum, interface, or struct

Compilation error (line 3, col 12): Identifier expected

Compilation error (line 3, col 14): Expected class, delegate, enum, interface, or struct

Compilation error (line 3, col 29): Expected class, delegate, enum, interface, or struct

Compilation error (line 3, col 38): Expected class, delegate, enum, interface, or struct

Compilation error (line 10, col 25): Expected class, delegate, enum, interface, or struct

Compilation error (line 11, col 9): Type or namespace definition, or end-of-file expected

围绕它

public class MyClass

{

    // your code

}

留给我

Compilation error (line 8, col 21): Identifier expected

Compilation error (line 8, col 22): ) expected

Compilation error (line 10, col 23): ) expected

Compilation error (line 10, col 24): ; expected

Compilation error (line 10, col 24): Invalid expression term ')'

Compilation error (line 10, col 25): ; expected

Compilation error (line 14, col 23): ) expected

Compilation error (line 14, col 24): ; expected

Compilation error (line 14, col 24): Invalid expression term ')'

Compilation error (line 14, col 25): ; expected

Compilation error (line 18, col 23): ) expected

Compilation error (line 18, col 24): ; expected

Compilation error (line 18, col 24): Invalid expression term ')'

Compilation error (line 18, col 25): ; expected

修复丢失的n和foreach到

string[] strArray = new string[10];

int i = 0;

var data = new [] {"1","2","3","4"};

foreach (var example in data)

{

     // your inner code

}

留给我

Compilation error (line 11, col 23): ) expected

Compilation error (line 11, col 24): ; expected

Compilation error (line 11, col 24): Invalid expression term ')'

Compilation error (line 11, col 25): ; expected

Compilation error (line 15, col 23): ) expected

Compilation error (line 15, col 24): ; expected

Compilation error (line 15, col 24): Invalid expression term ')'

Compilation error (line 15, col 25): ; expected

Compilation error (line 19, col 23): ) expected

Compilation error (line 19, col 24): ; expected

Compilation error (line 19, col 24): Invalid expression term ')'

Compilation error (line 19, col 25): ; expected

修复内部条件

    if (i==1)

    {

        strArray[i] = "There is";

    }

    if (i==2)

    {

        strArray[i] = "is no";

    }

    if (i==3)

    {

        strArray[i] = "no spoon.";

    }

    i = i + 1;

导致缺少公共静态 Main，修复导致

public class MyClass

{

    public static void Main(string[] args)

    {

        string[] strArray = new string[10];

        int i = 0;

        var data = new[]{"1", "2", "3", "4"};

        foreach (var example in data)

        {

            if (i == 1)

            {

                strArray[i] = "There is";

            }

            if (i == 2)

            {

                strArray[i] = "is no";

            }

            if (i == 3)

            {

                strArray[i] = "no spoon.";

            }

            i = i + 1;

        }

    }

}

一个运行没有错误的程序。

在此过程中没有任何地方弹出您的错误消息。

Answer 2

如果输出是一个返回类型为 void 的函数，则不能将其值赋给 strArray[i]。在每种情况下，确保函数的返回值不为空。

此外，问题可能在于使用foreach，因此将其替换为 for循环，因为更改foreach的枚举器可能会产生问题。

Answer 3

尝试删除 void 类型或 string[] argsinsideMain(string[] args)

也（不是另一种解决方案）但是如果你必须把它改进

if(condtion==1){...}

if(condtion==2){...}

if(condtion==3){...}

等等

更好的做法是将其替换为 Switch，这样您的程序就不会在每次调用方法时检查大量 if