Let's create a program that asks for the temperature of the water and then decides what state it is in. The state can be liquid, steam or ice.

public static void WaterState(int temperature)
{
    string state = "";
    if (temperature > 100)
    {
        state = "steam";
    }
    else if (temperature < 0)
    {
        state = "ice";
    }
    else
    {
        state = "liquid";
    }
    Console.WriteLine(state);
}