C# if 簡寫 [ ?: 運算子 ]

資料來源:https://docs.microsoft.com/zh-tw/dotnet/csharp/language-reference/operators/conditional-operator

int input = Convert.ToInt32(Console.ReadLine());  
string classify;  

// if-else construction.  
if (input > 0)  
    classify = “positive”;  
else  
    classify = “negative”;  

// ?: conditional operator.  
classify = (input > 0) ? “positive” : “negative”;