如何正确使用if语句？

userInput是一个字符串,您试图将它与int(100)进行比较.用户输入需要先转换为int.

int i;

// TryParse() returns true/false depending on whether userInput is an int

if (int.TryParse(userInput, out i))
{
    if (i > 100)
    {
        Console.WriteLine("I hate myself");
    }
    else
    {
        Console.WriteLine("I love myself");
    }
}
else
{
    Console.WriteLine("Input was not a valid number.");
}