C#•13mo ago

❔ System.ArgumentOutOfRangeException: Index and length must refer to a location within the string.

I've been programming for a handful of years, but never to a level of complexity i've been comfortable with in C#, however now in university me and a friend have been taked with creating a small little programming language transpiler as a side project by our tutor. It's a simple Console application which can read information and then will (not complete yet) dump it into a C# file. Somehow I managed to do this in python before, but C# is giving me some headache. Code:

using System;
using System.IO;
using System.Collections.Generic;
internal class Program
{
    public static void Main(string[] args)
    {
        // Create a string array for all items due to be compiled
        List<string> ghouLines = new List<string>();
        string buildDirectory = Directory.GetCurrentDirectory(); // Build directory
        while (true) {
            string input = Console.ReadLine();
            // Variables
            if (input.Substring(0,3) == "mut") {
                int equals = input.IndexOf('=') - 1;
                string variableName = input.Substring(3,equals);
                int endArg = input.IndexOf(';');
                string variableData = input.Substring(equals,endArg);
                ghouLines.Add($"var {variableName} {variableData};");
            }
            ghouLines.ForEach(i => Console.Write("{0}\t", i)); // DEBUG
        }
    }
}

using System;
using System.IO;
using System.Collections.Generic;
internal class Program
{
    public static void Main(string[] args)
    {
        // Create a string array for all items due to be compiled
        List<string> ghouLines = new List<string>();
        string buildDirectory = Directory.GetCurrentDirectory(); // Build directory
        while (true) {
            string input = Console.ReadLine();
            // Variables
            if (input.Substring(0,3) == "mut") {
                int equals = input.IndexOf('=') - 1;
                string variableName = input.Substring(3,equals);
                int endArg = input.IndexOf(';');
                string variableData = input.Substring(equals,endArg);
                ghouLines.Add($"var {variableName} {variableData};");
            }
            ghouLines.ForEach(i => Console.Write("{0}\t", i)); // DEBUG
        }
    }
}

Input:

mut a = 3;

mut a = 3;

43 Replies

AJOP•13mo ago

Error:

Unhandled Exception:
System.ArgumentOutOfRangeException: Index and length must refer to a location within the string.
Parameter name: length
  at System.String.Substring (System.Int32 startIndex, System.Int32 length) [0x0004c] in <baaab171478d4061bd9316f48a642f06>:0 
  at Program.Main (System.String[] args) [0x00051] in <f464cec0fa31423aa8525a46e0cd2e84>:0 
[ERROR] FATAL UNHANDLED EXCEPTION: System.ArgumentOutOfRangeException: Index and length must refer to a location within the string.
Parameter name: length
  at System.String.Substring (System.Int32 startIndex, System.Int32 length) [0x0004c] in <baaab171478d4061bd9316f48a642f06>:0 
  at Program.Main (System.String[] args) [0x00051] in <f464cec0fa31423aa8525a46e0cd2e84>:0

Unhandled Exception:
System.ArgumentOutOfRangeException: Index and length must refer to a location within the string.
Parameter name: length
  at System.String.Substring (System.Int32 startIndex, System.Int32 length) [0x0004c] in <baaab171478d4061bd9316f48a642f06>:0 
  at Program.Main (System.String[] args) [0x00051] in <f464cec0fa31423aa8525a46e0cd2e84>:0 
[ERROR] FATAL UNHANDLED EXCEPTION: System.ArgumentOutOfRangeException: Index and length must refer to a location within the string.
Parameter name: length
  at System.String.Substring (System.Int32 startIndex, System.Int32 length) [0x0004c] in <baaab171478d4061bd9316f48a642f06>:0 
  at Program.Main (System.String[] args) [0x00051] in <f464cec0fa31423aa8525a46e0cd2e84>:0

Angius•13mo ago

Well, one of the substrings is trying to access a part of the string that doesn't exist Using a debugger would help to figure out what the string is at which time

AJOP•13mo ago

Hm okay thank you, i'll look into that and get back to you @ZZZZZZZZZZZZZZZZZZZZZZZZZ any specific way to do that in VSCode with Mono, i'm on macOS 🤣 - yes i do realise i shot myself in the foot there

Angius•13mo ago

Why tf are you using Mono?

AJOP•13mo ago

idk was recommended by our uni

Angius•13mo ago

They're full of shit then

AJOP•13mo ago

I don't do a lot of C# development 💀

Angius•13mo ago

.NET nowadays is fully cross-platform, no need for workarounds like Mono

AJOP•13mo ago

oh fr?

Angius•13mo ago

Just get a .NET 7 SDK and you're good For debugging, get the "C# Dev Kit" extension for VS Code

AJOP•13mo ago

i assume microsoft publishes the binary links for it alright I already have the c# DEV KIT * sorry caps lock

Angius•13mo ago

Ypu're already good, then

AJOP•13mo ago

anything else I need to compile & run

Angius•13mo ago

Nope Just the SDK

AJOP•13mo ago

Right, is that an extension or binary?

Angius•13mo ago

Wym?

AJOP•13mo ago

how would I install it on macOS is there a download page or is it a VSCode extension

Angius•13mo ago

https://dotnet.microsoft.com/en-us/download/dotnet/7.0

Angius•13mo ago

AJOP•13mo ago

Cool this it infuriates me I was using mono 💀 @ZZZZZZZZZZZZZZZZZZZZZZZZZ it says there is no C# project currently loaded

Angius•13mo ago

Where does it say that?

AJOP•13mo ago

Angius•13mo ago

Well, do you have a project? Or is it just a loose .cs file?

AJOP•13mo ago

loose .cs file

Angius•13mo ago

You need a project dotnet new console to create a new console project, for example

AJOP•13mo ago

right, tysm still says the same I moved the program to Program.cs

Angius•13mo ago

Close VS Code, go to the directory with your .csproj file, open VS Code there?

AJOP•13mo ago

it works, but it's requiring an input and i don't know where i can place it my terminal is blank 🙃 Sorry i get these are quite nooby questions, it'd be mildly easier if i had access to standard visual studio tbh

Angius•13mo ago

There's always Rider If you're a student you can get the license for free $freerider

MODiX•13mo ago

There are two ways to get Rider for free: Being a student: https://www.jetbrains.com/community/education/#students Using it for an OSS project: https://www.jetbrains.com/community/opensource/#support

Angius•13mo ago

To be honest, dunno how to use the debugger in VS Code

AJOP•13mo ago

Neither 💀 I just bodge my way until it works 😺 👍

Angius•13mo ago

https://code.visualstudio.com/docs/csharp/debugging

Debugging C# in Visual Studio Code

See how you can run and debug your C# source code

AJOP•13mo ago

thank you It's quite late so i'll handle that tomorrow but thanks for all your help

Angius•13mo ago

Anytime

Will•13mo ago

**three!! https://www.jetbrains.com/rider/nextversion/

JetBrains

Early Access Program - Rider: Cross-platform .NET IDE

.NET IDE based on the IntelliJ platform and ReSharper. Supports C#, ASP.NET, ASP.NET MVC, .NET Core, Unity and Xamarin

g00dSoup•13mo ago

@AJStrong Visual Studio is the best for C# debugging. You can get the free community version

Angius•13mo ago

Not on Mac or Linux, tho

g00dSoup•13mo ago

Oh no rippp

AJOP•13mo ago

Which are my two primary operating systems It’s fine I have a spare laptop I can throw Win11 on, that was my plan anyway

Angius•13mo ago

Get yourself Rider, you won't regret it

AJOP•13mo ago

I will ❤️ I love JetBrains tbh They better have a Dracula theme >:3

Accord•13mo ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ System.ArgumentOutOfRangeException: Index and length must refer to a location within the string.