Develop Reference

Get values from a comma separated string containing less than a value

I am attempting to compare a comma separated string against a decimal variable and find only the amounts less than my variable.
The problem I'm having is my string looks like so:
1usd,5usd,10usd,20usd
I was able to separate the string into a collection by using the comma separator and regex split, but I don't think this is the best approach since I need to check just the value and reconstruct with the us and comma seperation.
A real world example my program will be handling is
decimal changeAvil = 10
notesSet = 1usd,5usd,10usd,20usd
Result should be notesSet = 1usd,5usd

Its not the prettiest code that has ever been written, but is does the job.
I use Linq to select the prefixes of the strings that are numbers, and then compare these to the value of changeAvil.
using System;
using System.Linq;
namespace stack
{
class Program
{
static void Main(string[] args)
{
decimal changeAvil = 10;
var noteSet = "1usd,5usd,10usd,20usd";
var notes = noteSet.Split(',');
var dict =
notes.ToDictionary(
x => int.Parse(new string(x.TakeWhile(c => char.IsNumber(c))
.ToArray())), // key
x => x); // value
var selection = dict.Where(kvp => kvp.Key <= changeAvil)
.Select(kvp => kvp.Value)
.ToList();
foreach (var s in selection) {
Console.WriteLine(s);
}
}
}
}
The solution returns 1usd, 5usd, and 10usd. If your do not want 10usd to be part of the result change kvp.Key <= changeAvil to kvp.Key < changeAvil in the Where clause of the Linq expression.

You can use split command and remove the letters 'usd' and then iterate through the array and compare
decimal changeAvil = 10
notesSet = 1usd,5usd,10usd,20usd
string noteset_new = noteset.Replace('usd',''); //remove usd
string[] noteset_array = noteset_new.split[',']; //split in to array
now you can iterate the above noteset_array and do what every you want to do.

Using replace and split on the string is using two iterations through the strings characters.
A better way to get the array will be to first add a comma to the end of the string and then use split:
notesSet = 1usd,5usd,10usd,20usd
string[] noteset_array = (notesSet + ',').split['usd,']; //split in to array

Read specific values out of a text-file and put them in a list

I have a text-file with many lines, each line looks like this:
"string string double double" between each value is a space. I'd like to read out the first string and last double of every line and put these two values in a existing list. That is my code so far, but it doesnt really work.
private void bOpen_Click(object sender, RoutedEventArgs e)
{
bool exists = File.Exists(#"C:\Users\p2\Desktop\Liste.txt");
if (exists == true)
{
StringBuilder sb = new StringBuilder();
using (StreamReader sr = new StreamReader(#"C:\Users\p2\Desktop\Liste.txt"))
{
Vgl comp = new Vgl();
comp.name = Abzahlungsdarlehenrechner.zgName;
comp.gErg = Abzahlungsdarlehenrechner.zgErg;
GlobaleDaten.VglDaten.Add(comp);
int i = 0;
string line = File.ReadLines(#"Liste.txt").Skip(0).Take(1).First();
while ((line = sr.ReadLine()) != null)
{
sb.Append((line));
listBox.Items.Add(line);
GlobaleDaten.VglDaten.Add(comp);
i++;
}
}
}
I have already read this, but it didnt help How do I read specific value[...]

You can try Linq:
var source = File
.ReadLines(#"C:\Users\p2\Desktop\Liste.txt")
.Select(line => line.Split(' '))
.Select(items => new Vgl() {
name = items[0],
gErg = double.Parse(items[3])
});
// If you want to add into existing list
GlobaleDaten.VglDaten.AddRange(source);
// If you want to create a new list
//List<Vgl> list = source.ToList();

how about
List<Vgl> Result = File.ReadLines(#"C:\Users\p2\Desktop\Liste.txt")
.Select(x => new Vgl()
{
name = x.Split(' ').First(),
gErg = decimal.Parse(x.Split(' ').Last(), NumberStyles.AllowCurrencySymbol)
})
.ToList();
I would avoid storing money within doulbe values because this could lead to rounding issues. Use decimal instead. Examples here: Is a double really unsuitable for money?

You can use:
string[] splitBySpace = line.Split(' ');
string first = splitBySpace.ElementAt(0);
decimal last = Convert.ToDecimal(splitBySpace.ElementAt(splitBySpace.Length - 1));
Edit : To Handle Currency symbol:
string[] splitBySpace = line.Split(' ');
string pattern = #"[^0-9\.\,]+";
string first = splitBySpace.ElementAt(0);
string last = (new Regex(pattern)).Split(splitBySpace.ElementAt(splitBySpace.Length - 1))
.FirstOrDefault();
decimal lastDecimal;
bool success = decimal.TryParse(last, out lastDecimal);

I agree with #Dmitry and fubo, if you are looking for alternatives, you could try this.
var source = File
.ReadLines(#"C:\Users\p2\Desktop\Liste.txt")
.Select(line =>
{
var splits = line.Split(' '));
return new Vgl()
{
name = splits[0],
gErg = double.Parse(splits[3])
};
}

use string.split using space as the delimiter on line to the string into an array with each value. Then just access the first and last array element. Of course, if you aren't absolutely certain that each line contains exactly 4 values, you may want to inspect the length of the array to ensure there are at least 4 values.
reference on using split:
https://msdn.microsoft.com/en-us/library/ms228388.aspx

Read the whole file as a string.
Split the string in a foreach loop using \r\n as a row separator. Add each row to a list of strings.
Iterate through that list and split again each record in another loop using space as field separator and put them into another list of strings.
Now you have all the four fields containig one row. Now just use First and Last methods to get the first word and the last number.

C#: Getting Substring between two different Delimiters

I have problems splitting this Line. I want to get each String between "#VAR;" and "#ENDVAR;". So at the End, there should be a output of:
Variable=Speed;Value=Fast;
Variable=Fabricator;Value=Freescale;Op==;
Later I will separate each Substring, using ";" as a delimiter but that I guess wont be that hard. This is how a line looks like:
#VAR;Variable=Speed;Value=Fast;Op==;#ENDVAR;#VAR;Variable=Fabricator;Value=Freescale;Op==;#ENDVAR;
I tried some split-options, but most of the time I just get an empty string. I also tried a Regex. But either the Regex was wrong or it wasnt suitable to my String. Probably its wrong, at school we learnt Regex different then its used in C#, so I was confused while implementing.
Regex.Match(t, #"/#VAR([a-z=a-z]*)/#ENDVAR")
Edit:
One small question: I am iterating over many lines like the one in the question. I use NoIdeas code on the line to get it in shape. The next step would be to print it as a Text-File. To print an Array I would have to loop over it. But in every iteration, when I get a new line, I overwrite the Array with the current splitted string. I put the Rest of my code in the question, would be nice if someone could help me.
string[] w ;
foreach (EA.Element theObjects in myPackageObject.Elements)
{
theObjects.Type = "Object";
foreach (EA.Element theElements in PackageHW.Elements)
{
if (theObjects.ClassfierID == theElements.ElementID)
{
t = theObjects.RunState;
w = t.Replace("#ENDVAR;", "#VAR;").Replace("#VAR;", ";").Split(new string[] { ";" }, StringSplitOptions.RemoveEmptyEntries);
foreach (string s in w)
{
tw2.WriteLine(s);
}
}
}
}
The piece with the foreach-loop is wrong pretty sure. I need something to print each splitted t. Thanks in advance.

you can do it without regex using
str.Replace("#ENDVAR;", "#VAR;")
.Split(new string[] { "#VAR;" }, StringSplitOptions.RemoveEmptyEntries);
and if you want to save time you can do:
str.Replace("#ENDVAR;", "#VAR;")
.Replace("#VAR;", ";")
.Split(new string[] { ";" }, StringSplitOptions.RemoveEmptyEntries);

You can use a look ahead assertion here.
#VAR;(.*?)(?=#ENDVAR)
If your string never consists of whitespace between #VAR; and #ENDVAR; you could use the below line, this will not match empty instances of your lines.
#VAR;([^\s]+)(?=#ENDVAR)
See this demo

Answer using raw string manipulation.
IEnumerable<string> StuffFoundInside(string biggerString)
{
var closeDelimeterIndex = 0;
do
{
int openDelimeterIndex = biggerString.IndexOf("#VAR;", startingIndex);
if (openDelimeterIndex != -1)
{
closeDelimeterIndex = biggerString.IndexOf("#ENDVAR;", openDelimeterIndex);
if (closeDelimiterIndex != -1)
{
yield return biggerString.Substring(openDelimeterIndex, closeDelimeterIndex - openDelimiterIndex);
}
}
} while (closeDelimeterIndex != -1);
}
Making a list and adding each item to the list then returning the list might be faster, depending on how the code using this code would work. This allows it to terminate early, but has the coroutine overhead.

Use this regex:
(?i)#VAR;(.+?)#ENDVAR;
Group 1 in each match will be your line content.

(If you don't like regexs)
Code:
var s = "#VAR;Variable=Speed;Value=Fast;Op==;#ENDVAR;#VAR;Variable=Fabricator;Value=Freescale;Op==;#ENDVAR;";
var tokens = s.Split(new String [] {"#ENDVAR;#VAR;"}, StringSplitOptions.None);
foreach (var t in tokens)
{
var st = t.Replace("#VAR;", "").Replace("#ENDVAR;", "");
Console.WriteLine(st);
}
Output:
Variable=Speed;Value=Fast;Op==;
Variable=Fabricator;Value=Freescale;Op==;

Regex.Split works well but yields empty entries that have to be removed as shown here:
string[] result = Regex.Split(input, #"#\w+;")
.Where(s => s != "")
.ToArray();

I tried some split-options, but most of the time I just get an empty string.
In this case the requirements seem to be simpler than you're stating. Simply splitting and using linq will do your whole operation in one statement:
string test = "#VAR;Variable=Speed;Value=Fast;Op==;#ENDVAR;#VAR;Variable=Fabricator;Value=Freescale;Op==;#ENDVAR;";
List<List<string>> strings = (from s in test.Split(new string[]{"#VAR;",";#ENDVAR;"},StringSplitOptions.RemoveEmptyEntries)
let s1 = s.Split(new char[]{';'},StringSplitOptions.RemoveEmptyEntries).ToList<string>()
select (s1)).ToList<List<string>>();
the outpout is:
?strings[0]
Count = 3
[0]: "Variable=Speed"
[1]: "Value=Fast"
[2]: "Op=="
?strings[1]
Count = 3
[0]: "Variable=Fabricator"
[1]: "Value=Freescale"
[2]: "Op=="
To write the data to a file something like this will work:
foreach (List<string> s in strings)
{
System.IO.File.AppendAllLines("textfile1.txt", s);
}

Read file select column

I'm reading a .txt file that contains 5 columns, but I only want to add the 5th column to a listbox, I tried IndexOf and Remove but it doesn't work, any suggestions?

Within your inner reading loop you just use something like:
private static void Readfile(String filePath)
{
foreach(String line in ReadAllLines(filePath))
{
string[] tokens = line.Split(new char[] { 'X' });
listbox.Add(tokens[4]); // This should be your 5th column.
}
}
And replace the X with a comma, space, or whatever symbol you use to separate.

This should work for you but it assumes that the split will always be successful.
var columnFiveValues = File.ReadLines("fileName")
.Select(line => line.Split('\t')) // tsv
.Select(split => split[4]) // column 5
.ToArray(); // evaluate now

String Concatenation / Overwriting?

This is a program that reads in a CSV file, adds the values to a dictionary class and then analyses a string in a textbox to see if any of the words match the dictionary entry. It will replace abbreviations (LOL, ROFL etc) into their real words. It matches strings by splitting the inputted text into individual words.
public void btnanalyze_Click(object sender, EventArgs e)
{
var abbrev = new Dictionary<string, string>();
using (StreamReader reader = new StreamReader("C:/Users/Jordan Moffat/Desktop/coursework/textwords0.csv"))
{
string line;
string[] row;
while ((line = reader.ReadLine()) != null)
{
row = line.Split(',');
abbrev.Add(row[0], row[1]);
Console.WriteLine(abbrev);
}
}
string twitterinput;
twitterinput = "";
// string output;
twitterinput = txtInput.Text;
{
char[] delimiterChars = { ' ', ',', '.', ':', '\t' };
string text = twitterinput;
string[] words = twitterinput.Split(delimiterChars);
string merge;
foreach (string s in words)
{
if (abbrev.ContainsKey(s))
{
string value = abbrev[s];
merge = string.Join(" ", value);
}
if (!abbrev.ContainsKey(s))
{
string not = s;
merge = string.Join(" ", not);
}
;
MessageBox.Show(merge);
}
The problem so far is that the final string is outputted into a text box, but only prints the last word as it overwrites. This is a University assignment, so I'm looking for a push in the correct direction as opposed to an actual answer. Many thanks!

string.Join() takes a collection of strings, concatenates them together and returns the result. But in your case, the collection contains only one item: value, or not.
To make your code work, you could use something like:
merge = string.Join(" ", merge, value);
But because of the way strings work, this will be quite slow, so you should use StringBuilder instead.

This is the problem:
string not = s;
merge = string.Join(" ", not);
You are just joining a single element (the latest) with a space delimiter, thus overwriting what you previously put into merge.
If you want to stick with string you need to use Concat to append the new word onto the output, though this will be slow as you are recreating the string each time. It will be more efficient to use StringBuilder to create the output.
If your assignment requires that you use Join to build up the output, then you'll need to replace the target words in the words array as you loop over them. However, for that you'll need to use some other looping mechanism than foreach as that doesn't let you modify the array you're looping over.

Better to User StringBuilder Class for such purpose
http://msdn.microsoft.com/en-us/library/system.text.stringbuilder.aspx