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C# stream reader reading whitespaces and bypassing them

I am creating a program that reads a text file and gets the data then puts it into an array. My problem is that there are instances where a column is intended to be blank but the blank value must still be considered as a value but when my program reads the blank column, it reads the next value and puts it in the array where the value should be 0 or blank. I have tried to count the spaces between each column to make it a condition but the spaces are not reliable since the data varies in length. Any ideas about how I might do this?
Here is what my text data looks like.
Data1 Data2 Data3
1.325 1.57 51.2
2.2 21.85
12.5 25.13
15.85 13.78 1.85
I need my array to look like this
firstRow['1.325','1.57','51.2'];
secondRow['2.2','0','21.85'];

If your file is tab-splitted, use line.Split("\t") to get array of substrings of each line. Then, each substring you can convert into you data type. In your case it must be nullable, e,g, decimal?.

Here's a starting point if you have a list of headers in the order they appear in the data and if your values are always aligned to the headers.
import io, csv, sys
data = '''\
Data 1 Data 2 Data 3
1.325 1.57 51.2
2.2 21.85
12.5 25.13
15.85 13.78 1.85
'''
headers = ['Data 1', 'Data 2', 'Data 3'] # order should match headers
f = io.StringIO(data)
h = f.readline()
indexes = [h.find(s) for s in headers]
rows = []
for line in f:
line = line[:-1] # strip trailing linefeed
d = {}
for key, index in list(zip(headers, indexes))[::-1]: # slice from the right
val = line[index:]
line = line[:index]
d[key] = val.strip()
rows.append(d)
writer = csv.DictWriter(sys.stdout, headers)
writer.writeheader()
writer.writerows(rows)

Since I have ran out of time, what I did was to count the number of spaces and if the spaces exceed by a number (in my case, 10) I'll add a value empty value in my array
string[] lsData = pData.Split(' ');
string[] lsData1 = new string[18];
int newArrayData = 0;
int spaceCounter = 0;
for (int i = 0; i < lsData.Length; i++)
{
if (lsData[i] != "")
{
lsData1[newArrayData] = lsData[i];
newArrayData++;
spaceCounter = 0;
}
else
{
spaceCounter++;
}
if (spaceCounter >= 10)
{
lsData1[newArrayData] = "";
newArrayData++;
spaceCounter = 0;
}
}

c# Read lines from a file and replace with text from DataGridView Data

I am relatively new to c#, I am creating an windows application which would read all the lines from a text file. The user will input the string which needs to be replaced in Column[0] and the text with which it needs to be replaced in Column1 of the DataGridView control.
I have created two string arrays column0 and column1.
However, I am getting an error while replacing the string in line (column0, column1)
The following is my code:
string[] column0 = new string[dgvMapping.Rows.Count];
string[] column1 = new string[dgvMapping.Rows.Count];
int j = 0;
foreach(DataGridViewRow row in dgvMapping.Rows)
{
if (!string.IsNullOrEmpty(Convert.ToString(row.Cells[0].Value)))
{
column0[j] = Convert.ToString(row.Cells[0].Value);
column1[j] = Convert.ToString(row.Cells[1].Value);
j++;
}
}
var _data = string.Empty;
String[] arrayofLine = File.ReadAllLines(ofd.FileName);
using (StreamWriter sw = new StreamWriter(ofd.FileName + ".output"))
{
for (int i = 0; i < arrayofLine.Length; i++)
{
string line = arrayofLine[i];
line = line.Replace(column0[i], column1[i]);
sw.WriteLine(line);
}
}
I am using OpenFileDialog to select the file.
The Error While Executing:

You are looping around a file of unknown number of lines, and assuming that the count of lines in the grid is exactly the same as that of the file. Your code will only work if both the file and the gridView have the same number of lines.
One of the solutions, is to loop over the array of lines (as you have already did), and search for the GridViewRow in which the current line contains a key in your DGV. If this is the case, then replace all the occurences of the key by the value (obtained from the gridView) in that line, otherwise do nothing.
Check out the code below :
// Convert the row collection to a list, so that we could query it easily with Linq
List<DataGridViewRow> mySearchList = dataGridView1.Rows.Cast<DataGridViewRow>().ToList();
const int KEY_INDEX = 0; // Search index in the grid
const int VALUE_INDEX = 1; // Value (replace) index in the grid
for (int i = 0; i < arrayofLines.Length; i++)
{
string line = arrayofLines[i];
// Get data grid view Row where this line contains the key string
DataGridViewRow matchedRow = mySearchList.FirstOrDefault(obj => line.Contains(obj.Cells[KEY_INDEX].Value.ToString()));
// If this row exists, replace the key with the value (obtained from the grid)
if (matchedRow != null)
{
string key = matchedRow.Cells[KEY_INDEX].Value.ToString();
string value = matchedRow.Cells[VALUE_INDEX].Value.ToString();
line = line.Replace(key, value);
sw.WriteLine(line);
}
else
{
// Otherwise, do nothing
}
}

Stuartd is correct… there are more lines in the file than there are elements to search. I am not sure what the search is doing in a sense that it seems somewhat limited. The code appears to search for each item depending on what line it is. The searched value in column 0 and the replace value in column 1 of row 0… will only replace those values for the FIRST line in the file. The DataGridViews second row values will search/replace only the SECOND line and so on. This seems odd.
Example the two string arrays (column0 and column1) have sizes set to the number of rows in dgvMapping. Let’s say there are 5 rows in the grid, then the array sizes will be 5 strings. When you start the loop to write the strings, the loop starts at 0 and stops at the number of lines in the file. The code uses this i variable as an index into the two arrays. If there are more lines in the file, than there are rows in the grid… then you will get the error.
Again, this seems odd to do the search and replace this way. Assuming you want to search for EACH term in all the rows in column 0 and replace the found searched string with the replace string in column 1, then you will need to loop through EACH row of the grid for EACH line in the file. This will replace ALL the search/replace terms in the grid with ALL the lines in the file. If this is what you what to accomplish below is one way to achieve this, however…there are possibly better ways to accomplish this.
The code below reads the file into one big string. Then the code loops through ALL the grid rows to search/replace the strings in the big string. Hope this helps.
string bigString = File.ReadAllText(ofd.FileName);
try {
using (StreamWriter sw = new StreamWriter(ofd.FileName + ".output")) {
for (int k = 0; k < dgvMapping.Rows.Count; k++) {
if (dgvMapping.Rows[k].Cells[0].Value != null && dgvMapping.Rows[k].Cells[1].Value != null) {
string searchTerm = dgvMapping.Rows[k].Cells[0].Value.ToString();
string replaceTerm = dgvMapping.Rows[k].Cells[1].Value.ToString();
if (searchTerm != "") {
bigString = bigString.Replace(searchTerm, replaceTerm);
} else {
// one of the terms is empty
}
} else {
// one of the terms is null}
}
}
sw.WriteLine(bigString);
}
}
catch (Exception ex) {
MessageBox.Show("Write Erro: " + ex.Message);
}

How do I read a matrix from a file into an array

Hey guys Im trying to be able to save an array from a text file but I'm at my wits end trying to figure out how to save it. I can print all the elements of the matrix as can be seen from the text file.
Sample input:
1 2 3 4 5
2 3 4 5 6
3 4 5 6 7
1 2 3 4 5
I keep getting an index out of range exception. Not sure what's happening.
Hopefully you guys understand what im trying to do.
Here's what I have so far:
class Program
{
static void Main(string[] args)
{
string input =
#"C:\Users\Nate\Documents\Visual Studio 2015\Projects\Chapter 15\Chapter 15 Question 5\Chapter 15 Question 5\TextFile1.txt";
StreamReader reader = new StreamReader(input);
List<string> list = new List<string>();
char[] unwanted = new char[] { ' ' };
using (reader)
{
int row = 0;
int column = 0;
string line = reader.ReadLine();
while (line != null)
{
string[] numbersString = line.Split(unwanted);
int[,] numbersInt = new int [ row, numbersString.Length];
foreach (string a in numbersString)
{
Console.Write("{0} ",a);// this is to check that the array was read in the right order
numbersInt[row, column] = int.Parse(a);
column++;
}
line = reader.ReadLine();
Console.WriteLine();
row++;
}
}
}
}

I suggest using jugged arrays (array of array int[][]) instead of 2D ones; in that case the solution will be quite simple, something like this (Linq):
int[][] matrix = File
.ReadLines(#"C:\myFile.txt")
.Split(new Char[] {' ', '\t'}, StringSplitOptions.RemoveEmptyEntries)
.Select(items => items
.Select(item => int.Parse(item))
.ToArray())
.ToArray();
Test (let's print out the matrix):
String report = String.Join(Environment.NewLine, matrix
.Select(line => String.Join(" ", line)));
Console.Write(report);

This change in your while should do the trick:
while (line = file.ReadLine()) != null)
{
...
}
Source: MSDN

You appear to be creating your instance of numbersInt inside your while loop. This means that with each pass of the loop you will re-create the array and when the loop exits the array will be lost. Move the declaration for numberInt to outside of the while loop.

Your immediate issue is that your code does not reset column back to zero after reading each line. Move int column = 0 into the while loop to fix this issue.
The second issue is numbersInt allocation. You create it for each line, which is not right, because it's a 2-D array. You need to create it before the loop, but of course you can't, because you don't know how many lines you are going to have. One approach is to use a dynamic data structure, and add one row at a time to it.
You can greatly simplify your code by using File.ReadAllLines method in combination with LINQ, because this would let you get rid of a lot of simple code. Now you can check how many lines you have before creating your 2-D array, and you could fill it in much easier as well:
var allRows = File
.ReadLines(#"C:\Users\Nate\Documents\Visual Studio 2015\Projects\Chapter 15\Chapter 15 Question 5\Chapter 15 Question 5\TextFile1.txt")
.Select(line => line.Split(unwanted).Select(int.Parse).ToList())
.ToList();
If you are OK with an array of arrays, you don't need to do anything: allRows is a 2-D structure of rows and columns containing your matrix.
If you must convert it to a 2-D array, you can do it with a pair of nested for loops:
if (allRows.Count == 0) {
// ... The file has no data - handle this error
}
var matrix = new int[allRows.Count, allRows[0].Count];
for (int row = 0 ; row != allRows.Count ; row++) {
for (int col = 0 ; col != allRows[0].Count ;col++) {
matrix[row, col] = allRows[row][col];
}
}

C# Array of List Index out of bounds

I've made a program that extracts some info from a file , do some operations with it and store it back on a list.
Following this link:
Are 2 dimensional Lists possible in c#?
I've been able to create a class with a list who would suit my needs. But after some debugging i've found that i was overwriting the list on each loop iteration.
Then i decided to make an array of lists - followed this link:
How to create an array of List<int> in C#?
Created an array of lists, initialized it and added elements. But when it needs to move to the next list position , it throws the out of boundaries exception.
I've tried a few things (readed about race condition) but none of 'em worked.
The problem will happen only when i open more than one file with my code ; otherwise it works perfectly.
Exception is thrown at xmldata , in the last iteration of the current file.
Ex: Selected two files, each one will add five elements. In the last element of the first file the exception will be thrown and there's data in the last element's position to be added.
Additional information: Index was outside the bounds of the array. (Exception thrown).
Any help will be appreciated. Thanks a lot.
Code:
List<xmldata>[] finalcontent = new List<xmldata>[9999];
finalcontent[listpos] = new List<xmldata>();//Initializing a list for each filename
foreach (Match m in matches)
{
Double[] numbers;
string aux;
aux = m.Groups[1].ToString();
aux = Regex.Replace(aux, #"\s+", "|");
string[] numbers_str = aux.Split(new[] { "|" }, StringSplitOptions.RemoveEmptyEntries);
numbers = new Double[numbers_str.Length];
for (int j = 0; j < numbers.Length; j++)
{
numbers[j] = Double.Parse(numbers_str[j], CultureInfo.InvariantCulture);
//Converts each number on the string to a Double number, store it in a position
//in the Double array
numbers[j] = numbers[j] / 100; //Needed calculus
numbers[j] = Math.Round(numbers[j], 3); //Storing numbers rounded
}
string values = String.Join(" ", numbers.Select(f => f.ToString()));
if (i <= colors_str.Length)
{
finalcontent[listpos].Add(new xmldata//The exception is thrown right here
{
colorname = colors_str[i],
colorvalues = values,
});//Closing list add declaration
}//Closing if
i++;
}//Closing foreach loop
Link to the file: https://drive.google.com/file/d/0BwU9_GrFRYrTT0ZTS2dRMUhIWms/view?usp=sharing

Arrays are fixed size, but Lists automatically resize as new items are added.
So instead, and since you're using Lists anyway, why not use a list of lists?
List<List<int>> ListOfListsOfInt = new List<List<int>>();
Then, if you really absolutely must have an array, then you can get one like this:
ListOfListsOfString.ToArray();

// Convert non-ascii characters to .
for (int jx = 0; jx < cnt; ++jx)
if (line[jx] < 0x20 || line[jx] > 0x7f) line[jx] = (byte)'.';
This is a big example, but check this one. You increase 'jx' before entering the statement, possibly exceeding the boundary of cnt?

Try changing the following:
if (i <= colors_str.Length)
to
if (i < colors_str.Length).
In fact I'm convinced that this is the problem.
This is because refereces begin at 0 and the last reference is length - 1, not length.

When using a list - it is better to use native functions for it.
List<xmldata>[] finalcontent = new List<xmldata>();
......
finalcontent[listpos] = new List<xmldata>(); insted of var _tmpVariable = new List<xmldata>();//Initializing a list for each filename
......
_tmpVariable.Add(new xmldata
{
colorname = colors_str[i],
colorvalues = values,
});//Closing list add declaration
fs.Close();//closing current file
listpos++;//Increment list position counter
finalcontent.Add(_tmpVariable); // add list into list
As there is no exception details it is hard to get where the exception is thrown.
It could be a list issue, a string issue or other (even file reading issue as well),
So please update this with current exception details.

Aligning strings into columns

I have a collection of strings that the user can add to or subtract from. I need a way to print the strings out in columns so that the 1st letter of each string aligned. However I the number of columns must be changeable during run time. Although the default is 4 columns the use can opt for any number from 1 to 6. I have no idea how to format an unknown quantity of string into an unknown number of columns.
Example Input:
it we so be a i o u t y z c yo bo go an
Example output of four columns
"Words" with 2 letters:
it so be we
yo bo go an
"Words" with 1 letter:
a i o u
t y z c
Note: not worried about parsing of the words I already have that in my code which I can add if helpful.

If you are trying to create fixed width columns, you can use string.PadLeft(paddingChar, width) and string.PadRight(paddingChar, width) when you are creating your rows.
http://msdn.microsoft.com/en-us/library/system.string.padleft.aspx
You can loop through your words and call .PadXXXX(width) on each word. It will automatically pad your words with the correct number of spaces to make your string the width you supplied.

You can divide the total line width by the number of columns and pad each string to that length. You may also want to trim extra long strings. Here's an example that pads strings that are shorter than the column width and trims strings that are longer. You may want to tweak the behavior for longer strings:
int Columns = 4;
int LineLength = 80;
public void WriteGroup(String[] group)
{
// determine the column width given the number of columns and the line width
int columnWidth = LineLength / Columns;
for (int i = 0; i < group.Length; i++)
{
if (i > 0 && i % Columns == 0)
{ // Finished a complete line; write a new-line to start on the next one
Console.WriteLine();
}
if (group[i].Length > columnWidth)
{ // This word is too long; truncate it to the column width
Console.WriteLine(group[i].Substring(0, columnWidth));
}
else
{ // Write out the word with spaces padding it to fill the column width
Console.Write(group[i].PadRight(columnWidth));
}
}
}
If you call the above method with this sample code:
var groupOfWords = new String[] { "alphabet", "alegator", "ant",
"ardvark", "ark", "all", "amp", "ally", "alley" };
WriteGroup(groupOfWords);
Then you should get output that looks like this:
alphabet alegator ant ardvark
ark all amp ally
alley