C
C#•4w ago
*ThE* *K!!nG*

✅ Bug

Hello guys, i'm a C# beginner and i found a bug in my code, however i don't know how to fix it, it may be easy for the experienced ones but i'm struggling, i tried using chat gpt but he didn't help me at all this is my code: 
 List<string> visitors = Console.ReadLine().Split(' ').ToList();

        while(true)
        {
            string command = Console.ReadLine();
            if (command == "END")
            {
                break;
            }
            string[] data = command.Split(" ");
            
            if (data[0] == "Add" && data[1] == "visitor")
            {
                string name = Console.ReadLine();
                visitors.Add(name);
            }
            else if (data[0] == "Add" && data[1] == "visitor" && data[2] == "on" && data[3] == "position")
            {
                string name = Console.ReadLine();
                int position = int.Parse(Console.ReadLine());
                visitors.Insert(position, name);
            }
            else if (data[0] == "Remove" && data[1] == "visitor" && data[2] == "on" && data[3] == "position")
            {
                int position = int.Parse(Console.ReadLine());
                visitors.RemoveAt(position);
            }
            else if (data[0] == "Remove" && data[1] == "last" && data[2] == "visitor")
            {
                visitors.RemoveAt(visitors.Count - 1);
            }
            else if (data[0] == "Remove" && data[1] == "first" && data[2] == "visitor")
            {
                visitors.RemoveAt(0);
            }

        }
        Console.WriteLine(string.Join(" ", visitors));
 List<string> visitors = Console.ReadLine().Split(' ').ToList();

        while(true)
        {
            string command = Console.ReadLine();
            if (command == "END")
            {
                break;
            }
            string[] data = command.Split(" ");
            
            if (data[0] == "Add" && data[1] == "visitor")
            {
                string name = Console.ReadLine();
                visitors.Add(name);
            }
            else if (data[0] == "Add" && data[1] == "visitor" && data[2] == "on" && data[3] == "position")
            {
                string name = Console.ReadLine();
                int position = int.Parse(Console.ReadLine());
                visitors.Insert(position, name);
            }
            else if (data[0] == "Remove" && data[1] == "visitor" && data[2] == "on" && data[3] == "position")
            {
                int position = int.Parse(Console.ReadLine());
                visitors.RemoveAt(position);
            }
            else if (data[0] == "Remove" && data[1] == "last" && data[2] == "visitor")
            {
                visitors.RemoveAt(visitors.Count - 1);
            }
            else if (data[0] == "Remove" && data[1] == "first" && data[2] == "visitor")
            {
                visitors.RemoveAt(0);
            }

        }
        Console.WriteLine(string.Join(" ", visitors));
Basically the bug is that whenever i write "Add visitor on position" it goes to the first condition because it's got "Add visitor" i tried switching the places but it just throws an error, i would appreciate some help
44 Replies
Salman
Salman•4w ago
instead of comparing the input like that perhaps you could have made a Menu instead and give the user option to chose whatever they want this doesn't look like a good way tbh
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
that's how my teacher taught me to do it tho
Salman
Salman•4w ago
also instead of comparing parts of the string like this you could've compared the whole input e.g 
if(command == "Add visitor on position")
if(command == "Add visitor on position")
It's still not a good way but a slightly better way because in this case you are comparing the whole command literally and that bug shouldn't happen
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
okay i'll try, thank you
Salman
Salman•4w ago
do you see the difference? that condition will compare the whole command instead of only comparing parts by parts which is not necessary
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
yes yes, i don't know how i didn't think of that 😅 i'm sorry, i've been coding for 2 months or something like that
Salman
Salman•4w ago
no it's totally fine also 
int position = int.Parse(Console.ReadLine());
int position = int.Parse(Console.ReadLine());
here what if user doesnt input a number but something random such as abcdf instead ? wont the program crash
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
yes it will
Salman
Salman•4w ago
so the solution is int.TryParse
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
that's js practice exercises provided by the Ministry of Education and Science
Salman
Salman•4w ago
string input = "123";
if (int.TryParse(input, out int number))
{
    Console.WriteLine($"Parsed number: {number}");
}
else
{
    Console.WriteLine("Invalid input");
}
string input = "123";
if (int.TryParse(input, out int number))
{
    Console.WriteLine($"Parsed number: {number}");
}
else
{
    Console.WriteLine("Invalid input");
}
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
oh so that's what tryparse is for
Salman
Salman•4w ago
yes
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
i was wondering what it's used for thank you 😅
Salman
Salman•4w ago
you are welcome $close
MODiX
MODiX•4w ago
If you have no further questions, please use /close to mark the forum thread as answered
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
it still doesnt work tho there's an exact output that u have to get on the website i'm looking at and you have to enter
Salman
Salman•4w ago
what doesn't work and how
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
one sec 
Ivan, Peter, Simona, Krasimir, Petya

Add visitor

Stoyan

Remove first visitor

Add visitor on position

Katya

3

END
Ivan, Peter, Simona, Krasimir, Petya

Add visitor

Stoyan

Remove first visitor

Add visitor on position

Katya

3

END
u have to enter this and get 
Peter Simona Krasimir Katya Petya Stoyan
Peter Simona Krasimir Katya Petya Stoyan
this but i get this as my output 
Peter, Simona, Krasimir, Petya
Peter, Simona, Krasimir, Petya
Salman
Salman•4w ago
share your renewed code
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
List<string> visitors = Console.ReadLine().Split(' ').ToList();

        while(true)
        {
            string command = Console.ReadLine();
            if (command == "END")
            {
                break;
            }
            
            if (command == "Add visitor")
            {
                string name = Console.ReadLine();
                visitors.Add(name);
            }
            else if (command == "Add visitor on Position")
            {
                string name = Console.ReadLine();
                int position = int.Parse(Console.ReadLine());
                visitors.Insert(position, name);
            }
            else if (command == "Remove visitor on position")
            {
                int position = int.Parse(Console.ReadLine());
                visitors.RemoveAt(position);
            }
            else if (command == "Remove last visitor")
            {
                visitors.RemoveAt(visitors.Count - 1);
            }
            else if (command == "Remove first visitor")
            {
                visitors.RemoveAt(0);
            }

        }
        Console.WriteLine(string.Join(" ", visitors));
List<string> visitors = Console.ReadLine().Split(' ').ToList();

        while(true)
        {
            string command = Console.ReadLine();
            if (command == "END")
            {
                break;
            }
            
            if (command == "Add visitor")
            {
                string name = Console.ReadLine();
                visitors.Add(name);
            }
            else if (command == "Add visitor on Position")
            {
                string name = Console.ReadLine();
                int position = int.Parse(Console.ReadLine());
                visitors.Insert(position, name);
            }
            else if (command == "Remove visitor on position")
            {
                int position = int.Parse(Console.ReadLine());
                visitors.RemoveAt(position);
            }
            else if (command == "Remove last visitor")
            {
                visitors.RemoveAt(visitors.Count - 1);
            }
            else if (command == "Remove first visitor")
            {
                visitors.RemoveAt(0);
            }

        }
        Console.WriteLine(string.Join(" ", visitors));
i'll make the TryParse thing later i just need to get the exact output 😅
Salman
Salman•4w ago
lemme test it out
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
sure
Salman
Salman•4w ago
just tested this and I got this output: Peter, Simona, Krasimir, Petya Stoyan
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
You need to get this: Peter Simona Krasimir Katya Petya Stoyan u copied and pasted the exact same thing i sent, right ohhh i found out why
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
No description
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
its because i'm writing Katya 3
Salman
Salman•4w ago
yes also
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
and its visitors.Insert(position, name); im writing the name first, then the position
Salman
Salman•4w ago
on the first line you shouldn't split the input based on the whitespace but based on the commas because what if a name contains the whitespace in itself? won't that create problem so instead do this: 
Console.ReadLine().Split(',').ToList();
Console.ReadLine().Split(',').ToList();
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
Okay yea i was gonna fix that later, i js wanted to get the right output
Salman
Salman•4w ago
yeah probably
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
oop no that's not the issue for some reason the program just skips the Add on position command
Salman
Salman•4w ago
public void Insert(int index, T item);
public void Insert(int index, T item);
index first, item after
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
where should i write that
Salman
Salman•4w ago
@ThE K!!nG in your code the command is being compared to Add on Position note that P is capital here while in the given input p is smaller that's just an example of how Insert should be used
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
ohhh yea 😭 i didn't notice that i'm so sorry imma go try it
Salman
Salman•4w ago
:catlost:
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
yea it worked i'm sorry, i'm trying my best 😭
Salman
Salman•4w ago
congrats
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
Thank you so much for helping me and sorry for disturbing you i hope u have a wonderful day/night!
Salman
Salman•4w ago
nah you are welcome you can close the thread
*ThE* *K!!nG*
*ThE* *K!!nG*OP•4w ago
okay! $close
MODiX
MODiX•4w ago
If you have no further questions, please use /close to mark the forum thread as answered

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