基本的C＃if语句查询

Question

I need to input 3 numbers, and then output the highest & lowest of the 3 numbers using IF commands. I have everything working, except I'm getting 1 largest number (correct) and 3 outputs of the lowest number (incorrect). Now I totally understand why they're all being displayed, I just do not know how to fix it. My code, once the integers have been defined by user input, is as follows:

if (num1 > num2 && num1 > num3)
{
    Console.WriteLine("Largest Number: " + num1);
}

if (num2 > num3)
{
    Console.WriteLine("Smallest Number: " + num3);
}
else
{
    Console.WriteLine("Smallest Number: " + num2);
}

and then duplicated 3 times, switching the respective integers. I understand what the issue is, it's that the second if command is correct for all 3 scenarios. I just... don't know how to fix it. I feel like I just need to join these two if statements together somehow but I'm unsure how to do this, or if it's even possible.

Answer 1

You can, and you will have to, on many instances nest blocks. This way, the second if will only be evaluated if the first was evaluated as true.

if (num1 > num2 && num1 > num3)
{
    Console.WriteLine("Largest Number: " + num1);

    if (num2 > num3)
    {
    Console.WriteLine("Smallest Number: " + num3);
    }
    else
    {
        Console.WriteLine("Smallest Number: " + num2);
    }
}

This is only to answer your most immediate problem, that is, the smallest number being displayed more than one time.

You might encounter others, for example, as others mentioned : What if two numbers are equals ?

Answer 2

To get the largest/lowest the best way is to have a variable to store the current max/min instead of checking every cases (permutation).

Something like

    int largest = int.MinValue;
    int smallest = int.MaxValue;

    if (num1 > largest)
        largest = num1;
    if (num2 > largest)
        largest = num2;
    if (num3 > largest)
        largest = num3;

    if (num1 < smallest)
        smallest = num1;
    if (num2 < smallest)
        smallest = num2;
    if (num3 < smallest)
        smallest = num3;

//output largest/smallest

Answer 3

No if statements necessary:

Console.WriteLine("Largest Number: " + Math.Max(Math.Max(num1, num2), num3));
Console.WriteLine("Smallest Number: " + Math.Min(Math.Min(num1, num2), num3));