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练习 ​

第一项挑战 ​

此模块包含两项代码挑战。第一项挑战强制要求根据数据类型拆分数据，并相应地连接或添加数据。

编写代码以实现业务规则 ​

循环访问值字符串中的每个值。

从以下代码行开始。

csharp
string[] values = { "12.3", "45", "ABC", "11", "DEF" };

添加实现以下业务规则所需的所有代码：

业务规则：

  • 规则 1：如果值是字母数字型，则连接它以形成消息
  • 规则 2：如果值是数字，则将其添加到总计值
  • 规则 3：确保结果与以下输出一致：
output
Message: ABCDEF
Total: 68.3

代码 ​

csharp
string[] values = { "12.3", "45", "ABC", "11", "DEF" };
string message = "";
decimal total = 0m;
foreach(string value in values){
    decimal result = 0m;
    if(decimal.TryParse(value, out result)){
        total += result;
    } else{
        message += value;
    }
}
Console.WriteLine($"Message: {message}\nTotal: {total}");

// Message: ABCDEF
// Total: 68.3

答案 ​

csharp
string[] values = { "12.3", "45", "ABC", "11", "DEF" };

decimal total = 0m;
string message = "";

foreach (var value in values)
{
    decimal number;
    if (decimal.TryParse(value, out number))
    {
        total += number;
    } else
    {
        message += value;
    }
}

Console.WriteLine($"Message: {message}");
Console.WriteLine($"Total: {total}");

第二项挑战 ​

考虑到收缩转换和扩大转换的影响，下面的挑战强制要求了解强制转换值的含义。

编写代码生成所需的输出 ​

从以下代码开始：

csharp
int value1 = 12;
decimal value2 = 6.2m;
float value3 = 4.3f;

// Your code here to set result1
Console.WriteLine($"Divide value1 by value2, display the result as an int: {result1}");

// Your code here to set result2
Console.WriteLine($"Divide value2 by value3, display the result as a decimal: {result2}");

// Your code here to set result3
Console.WriteLine($"Divide value3 by value1, display the result as a float: {result3}");

将代码注释替换为自己的代码来解决问题。

运行代码后，应会得到以下输出：

bash
Divide value1 by value2, display the result as an int: 2
Divide value2 by value3, display the result as a decimal: 1.4418604651162790697674418605
Divide value3 by value1, display the result as a float: 0.3583333

代码 ​

csharp
int value1 = 12;
decimal value2 = 6.2m;
float value3 = 4.3f;

int result1 = value1 / (Convert.ToInt32(value2));
Console.WriteLine($"Divide value1 by value2, display the result as an int: {result1}");

decimal result2 = value2 / (decimal)value3;
Console.WriteLine($"Divide value2 by value3, display the result as a decimal: {result2}");

float result3 = value3 / value1;
Console.WriteLine($"Divide value3 by value1, display the result as a float: {result3}");

// Divide value1 by value2, display the result as an int: 2
// Divide value2 by value3, display the result as a decimal: 1.4418604651162790697674418605
// Divide value3 by value1, display the result as a float: 0.3583333

答案 ​

csharp
int value1 = 12;
decimal value2 = 6.2m;
float value3 = 4.3f;

int result1 = Convert.ToInt32((decimal)value1 / value2);
Console.WriteLine($"Divide value1 by value2, display the result as an int: {result1}");

decimal result2 = value2 / (decimal)value3;
Console.WriteLine($"Divide value2 by value3, display the result as a decimal: {result2}");

float result3 = value3 / value1;
Console.WriteLine($"Divide value3 by value1, display the result as a float: {result3}");