c# - 将字符串与字符串数组进行匹配

Question

我有一个包含四个操作的数组，我想将它们与输入字符串进行匹配。

我的尝试:

string[] operations = {"add","sub","mul","div"};
string rawInput = Console.ReadLine();
string[] inputs = rawInput.Split(delims,StringSplitOptions.RemoveEmptyEntries);
firstInput = inputs[0].Trim();

foreach (string operation in operations) 
{
    if (firstInput.Contains(operation))
        Console.WriteLine("Valid operation: {0}",operation);
}

正如我所料，如果我输入 add、sub、mul 或 div，则会打印 Valid operation。

为了打印无效输入的消息，我添加了如下的 else 条件:

else
{
    Console.WriteLine("Invalid operation: {0}", firstInput);
    break;
}

如果我现在输入sub，我会得到:

无效操作:sub

如果我删除break语句并输入sub:

Invalid operation: sub
Valid operation: sub
Invalid operation: sub
Invalid operation: sub

如何修改逻辑以便我只收到一次正确的消息？

Answer 1

查看第一个输入是否在有效操作列表中，而不是相反(使用 LINQ):

if (operations.Contains(firstInput))
{
  Console.WriteLine("Valid operation: {0}", firstInput);
}
else
{
  Console.WriteLine("Invalid operation: {0}", firstInput);
}

如果像您所做的那样迭代列表，这是一个选项:

bool foundValidOP = false;
foreach (string operation in operations) 
{
    if (firstInput.Equals(operation, StringComparison.InvariantCultureIgnoreCase))
    {
        foundValidOP = true;
        break;
    }
}

if (foundValidOP)
{
  Console.WriteLine("Valid operation: {0}", firstInput);
}
else
{
  Console.WriteLine("Invalid operation: {0}", firstInput);
}