How can I validate these variables without an if else statement?

Question

I'm very new to c# so please excuse my lack of knowledge. I'm just trying to check the following:

"CardNumberLength" = 16
"CardPINLength" = 3
"CardNameHasSpace" 0 I don't want to use an if else statement, is there another way?

The code:

public bool Validate()
{
    CardNumberLength = Convert.ToString(GetCardNumber()).Length;

    CardPINLength = Convert.ToString(GetCardPIN()).Length;

    CardNameHasSpace = GetCardName().IndexOf(" ");
}

Why don't you want to use if? Its natural to use it to check **IF** something is ok. — Ralf, Nov 03 '21 at 20:17
Instead of `Convert.ToString(expr)` you can often use `expr.ToString()`. — Jeppe Stig Nielsen, Nov 03 '21 at 20:27

score 5 · Accepted Answer · answered Nov 03 '21 at 20:19

5

You could just return the boolean result:

return CardNumberLength == 16 && CardPINLength == 3 && CardNameHasSpace >= 0;

answered Nov 03 '21 at 20:19

Jan Köhler

5,817
5
26
35

My apologies, i should have said that i want it to check all 3 of these values, and if they are all correct (as listed in the description), i want it to return "true", if not, "false". – Alex Gottschalk Nov 03 '21 at 20:23
3

Exactly this happens in that statement :) Please note that `=` is an assignment and `==` is a comparison. – Jan Köhler Nov 03 '21 at 20:26

Dortimer · Answer 2 · 2021-11-03T20:35:54.447

If you absolutely had to do this without if tests, you could mash them together in a return statement. It's just a different syntax to express the same logic. I probably wouldn't suggest doing this without if tests though.

public bool Validate()
{
    return Convert.ToString(GetCardNumber()).Length == 16 //replaces CardNumberLength
        && Convert.ToString(GetCardPin()).Length == 3 // replaces CardPINLength
        && GetCardName().IndexOf(" ") < 1; // replaces CardNameHasSpace
}

GHOST · Answer 3 · 2021-12-18T12:15:18.240

-1

    public bool Validate()
    {
        int CardNumberLength = int.Parse(GetCardNumber().ToString().Length);
        int CardPINLength = int.Parse(GetCardPIN().ToString().Length);
        bool CardNameHasSpace = GetCardName().Contains(" ");
        
        return CardNumberLength == 16 && CardPINLength == 3 && !CardNameHasSpace
    }

using the .ToString() on an object is way better than Convert.ToString(), also you can check inside a string if it contains a certain string with the .Contains(string) function on a string.

edited Dec 18 '21 at 12:15

answered Nov 03 '21 at 20:26

GHOST

337
3
9

3

You’re assigning ToString().Length to a string… – Thomas Flinkow Nov 03 '21 at 20:36
@ThomasFlinkow I believe that breaks the `return` statement too – Dortimer Nov 03 '21 at 20:56
@ThomasFlinkow yea i was sort of not paying attention when i was writing that, i fixed it now – GHOST Nov 05 '21 at 22:12

Pasan Ratnayake · Answer 4 · 2021-11-03T20:37:39.350

-3

public bool Validate()
{
    CardNumberLength = Convert.ToString(GetCardNumber()).Length;
    CardPINLength = Convert.ToString(GetCardPIN()).Length;
    CardNameHasSpace = GetCardName().IndexOf(" ");

    return CardNumberLength == 16 && CardPINLength == 3 && CardNameHasSpace > -1;
}

Or

public bool Validate()
{
   CardNumberLength = Convert.ToString(GetCardNumber()).Length;
   CardPINLength = Convert.ToString(GetCardPIN()).Length;
   CardNameHasSpace = GetCardName().IndexOf(" ");

   if (CardNumberLength != 16)
      return false;
      
   if (CardPINLength != 3)
      return false;
      
   if (CardNameHasSpace == -1)
      return false;
  
   return true;
}

Perhaps, this helps you :)

edited Nov 03 '21 at 20:37

answered Nov 03 '21 at 20:19

Pasan Ratnayake

495
4
10

This is exactly what I was looking for, thank you. I didn't know about the try, catch function in C# just yet. – Alex Gottschalk Nov 03 '21 at 20:25
2

Throwing the exception seems kind of needless. At that point you might as well just return false – Dortimer Nov 03 '21 at 20:27
8

Please [don't use exceptions as control flow](https://stackoverflow.com/questions/729379/why-not-use-exceptions-as-regular-flow-of-control). – D M Nov 03 '21 at 20:27
I've just replaced the throw exception with return false and it does the job – Alex Gottschalk Nov 03 '21 at 20:31
@AlexGottschalk This uses if tests though – Dortimer Nov 03 '21 at 20:32
Sometimes OPs really don't know to explain what they are looking for. If it helps them, it helps them – Pasan Ratnayake Nov 03 '21 at 20:35
@AlexGottschalk please mark the answer that helped and close the thread – Pasan Ratnayake Nov 03 '21 at 20:36
@PasanRatnayake Even if they don't know how to explain it exactly, that is still a really bad idea. – Dortimer Nov 03 '21 at 20:39
I begun 2 days ago, so all code is helpful to me, even if it is deemed as wrong. I'm also new to this website, how do I close the tread xD – Alex Gottschalk Nov 03 '21 at 20:40
@AlexGottschalk I'm just sayin, this is a pretty key time for you to not learn bad habits. – Dortimer Nov 03 '21 at 20:42
@AlexGottschalk don't worry about it. Sometimes people forget who we are supposed to help. A moderator would probably close it soon. – Pasan Ratnayake Nov 03 '21 at 20:42
@Dortimer thank you very much for your help :) – Alex Gottschalk Nov 03 '21 at 20:44

How can I validate these variables without an if else statement?

4 Answers4