Why does class list become empty?

Question

0.00/5 (No votes)

See more:

Playing around, trying to figure out C#. The allFiveLetterWords list is either cleared by the time the possibilitiesTextBox_TextChanged event happens, or it is creating a temporary list with nothing in it at that point, because nothing is there at that point even though there was at the end of the Form1_Load event.

namespace wordleSolver
{
    public partial class Form1 : Form
    {
        public List<string> allWords = new List<string>();
        public List<string> allFiveLetterWords = new List<string>();
        public List<string> currentPossibilities = new List<string>();

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            string path = "D:\\Programs\\MyProgs\\wordleSolver\\words.txt";
            System.IO.StreamReader sr = new System.IO.StreamReader(path);

            while (!sr.EndOfStream)
            {
                string str = sr.ReadLine();
                allWords.Add(str);
            }
            sr.Close();

            foreach (string str in allWords)
            {
                if (str.Length == 5) allFiveLetterWords.Add(str);
            }
            currentPossibilities = allFiveLetterWords;
            foreach (string str in currentPossibilities)
            {
                possibilitiesListBox.Items.Add(str);
            }
        }



        private void possibilitiesTextBox_TextChanged(object sender, EventArgs e)
        {
            currentPossibilities.Clear();

            string possibleChars = possibilitiesTextBox.Text;

            int possibleCharsLen = possibleChars.Length;

            //THERE AIN'T NOTHING IN 'allFiveLetterWords' HERE!!!!!!!
            foreach (string str in allFiveLetterWords)
            {
                for (int i=0; i<5; ++i)
                {
                    for (int j=0; j<possibleCharsLen; ++j)
                    {
                        if (allFiveLetterWords[i][j] == possibleChars[j])
                        {
                            currentPossibilities.Add(str);
                            goto breakout;
                        }
                    }
            breakout:;
                }
            }
            possibilitiesListBox.Items.Clear();
            foreach (string str in currentPossibilities) {
                possibilitiesListBox.Items.Add(str);    
            }

        }
    }
}

What I have tried:

Swearing, more cursing, all the usual suspects.

Posted 7-Sep-22 21:58pm

David O'Neil

Updated 7-Sep-22 22:36pm

Add a Solution

3 solutions

Solution 1

Swearing and cursing may help you feel better about things, but they don't help fix software problems. What does help is the debugger. Assuming the file has lines, then allWords will contain entries.
If allWords has entries, they will be added to allFiveLetterWords only if the string length is five.

So if allFiveLetterWords is empty after the loop to fill it, I'd suspect the data source file isn't "clean" - I'd use the debugger to look at exactly what allWords contains, and check for any whitespace or punctuation which might be difficult to see (or invisible) but make the length of a word 6 or 7 with only 5 alpha characters.

Sorry, but we can't do any of that for you!

Posted 7-Sep-22 22:09pm

OriginalGriff

Comments

David O'Neil 8-Sep-22 4:13am

The 'allFiveLetterWords' contains 22,950 items at the end of the Form1_Load event. Thereby the swearing and cursing. I don't understand why it would empty itself out.

Solution 2

I am not a C# expert, but it looks there is a suspicious reference assigment:
In Form1_Load

Quote:
currentPossibilities = allFiveLetterWords;

Then, in possibilitiesTextBox_TextChanged.

Quote:
currentPossibilities.Clear();

I guess this magically clears allFiveLetterWords.

Replace (in Form1_Load)

Quote:
currentPossibilities = allFiveLetterWords;
foreach (string str in currentPossibilities)
{
possibilitiesListBox.Items.Add(str);
}

With

C#

foreach (string str in allFiveLetterWords)
{
    possibilitiesListBox.Items.Add(str);
}

Posted 7-Sep-22 22:36pm

CPallini

Updated 7-Sep-22 22:37pm

v2

Comments

David O'Neil 8-Sep-22 4:43am

Thank you.

CPallini 8-Sep-22 4:59am

You are welcome.

Add a Solution

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Chris Copeland · Accepted Answer · 2022-09-07T22:36:00

Your problem is with this line:

C#

currentPossibilities = allFiveLetterWords;

A list is allocated on the heap when you call new List<string>() and the address of that list is stored in the variable. When you access the variable (ie. calling .Add()) you're asking C# to find the list in the heap, then call the Add() method.

With the above, what you've done is said "the currentPossibilities variable should point to the same list as allFiveLetterWords". Then, in your text changed event you call:

C#

currentPossibilities.Clear();

Which also says "clear all values out of the list at the address of currentPosibilities", which also happens to be the same address as allFiveLetterWords. You can fix this easily by simply creating a new list:

C#

currentPossibilities = new List<string>(allFiveLetterWords);

This page has a fairly decent explanation of heap vs. stack[^]

Why does class list become empty?

3 solutions

Solution 1

Solution 2

Solution 3

Add your solution here

Preview 0

Why does class list become empty?

3 solutions

Solution 1

Solution 2

Solution 3

Add your solution here

Preview 0

Existing Members

...or Join us