Develop Reference

Can I shorten this code with a loop in C#?

I have this code written in C# but looks kind of "bad" and I would like to shorten it somehow and keep it clean and simple.
All this code works pretty fine but I want to know if there's any other way I can achieve the same thing.
EDIT: I forgot to mention that the firstLine has a bad date format attached with it, so it is like this: "This_is_my_first_line_20220126". So I split the string and then only join it with the corrected date. The problem is that I can never know how long the new string would be and I don't want to handle the code like this and go up to 100 parts.
Here's my code:
string correctDate = "26012022";
string[] lines = File.ReadAllLines("text.txt");
string firstLine = lines.FirstOrDefault();
//note: firstLine looks like this: This_is_my_first_line_20220126
string[] sub = firstLine.Split('_');
string name="";
if(sub.Length==2)
name = sub[0]+"_"+sub[1]+"_"+correctDate;
else if(sub.Length==3)
name = sub[0]+"_"+sub[1]+"_"+sub[2]+"_"correctDate;
...
else if(sub.Length==20)
name = sub[0]+"_"+ ... "_" + sub[19];
Now, my final name value should be "This_is_my_line_26012022" but I want it to depend on the length of the given string. So far I know that the maximum length would go up to 20 but I don't want my code to look like this. Can I shorten it somehow?

you can find the LastIndexOf the underscore and drop the date by using Substring:
string firstLine = "This_is_my_first_line_20220126";
string correctDate = "26012022";
string correctString = firstLine.Substring(0, firstLine.LastIndexOf("_") + 1) + correctDate;

Still a little perplexed with the split aproach, but this a way to join back all elements
string name = string.Join("_", sub.Take(sub.Length - 1).Append(correctDate));
Or use the substring method (and no need of all that split & join)
name = firstLine.Substring(0, firstLine.LastIndexOf("_") +1) + correctDate;

I forgot to mention that firstLine has a bad date format like "This_is_my_Line_20220125"
If you want to correct just the first line:
string correctDate = "26012022";
string[] lines = File.ReadAllLines("text.txt");
lines[0] = lines[0][..^8] + correctDate;
[..^8] uses C# 9's "indices and ranges" feature, that allows for a more compact way of taking a substring. It means "from the start of the string, up to the index 8 back from the end of the string".
If you get a wiggly line and possibly a messages like "... is not available in C# version X" you can use the older syntax, which would be more like lines[0] = lines[0].Remove(lines[0].Length - 8) + correctDate;
If you want to correct all lines:
string correctDate = "26012022";
string[] lines = File.ReadAllLines("text.txt");
for(int x = 0; x < lines.Length; x++)
lines[x] = lines[x][..^8] + correctDate;
If the incorrect date isn't always 8 characters long, you can use LastIndexOf('_') to locate the last _, and snip it to that point

How to parse, actually get number from string in c#?

I am trying to get only part with number. For example in input could be just number like 50, or string like: 50 and more. Also Number always will be on first place. And I want always to get only number from that. I tried like this, but this does not work:
double tendency;
var tendencyToString= Convert.ToString(tendency.ToString());
var tendencySplited = tendencyToString.Split(' ');
var tendencyNumber = tendencySplited[0];

You can extract the number from the string using a regular expression.
See an example below. One thing to pay an attention to are your locale settings as they influence the format of the double.
string pattern = #"^\d+\.\d+";
string input = "50.1 , or more";
Match m = Regex.Match(input, pattern, RegexOptions.IgnoreCase);
if (m.Success) {
double nr = Double.Parse(m.Value);
Console.WriteLine(nr);
}

So if i enter "507.89foo123,456bah" you want only 507 or you want
507.89? –
Please read, I write 50, not 50 with coma or something decimal. I just want 507 in your example
Well, then it's pretty easy:
string input = "50.1 , or more";
char[] digits = input.TakeWhile(Char.IsDigit).ToArray();
if(digits.Any())
{
string result = new string(digits); // "50"
// if you want an integer:
int number = int.Parse(result);
}

C#: Textbox to multiple strings

Just a C# beginner here that just build his first application and now wants to make some changes to make it more ideal.
Today I got three textboxes where the users type in year, month and project number.
When they click GO the application opens the respective folder: L:\2019\01\20190133
I would like to make it simpler, one textbox that gets divided into three strings (year, month, PO-number).
Any ideas? Sorry for the bad format of this post, feel free to correct/shame me :)
Current code:
private void button1_Click(object sender, System.EventArgs e)
{
int tbyear;
int tbmonth;
int tbpnr;
tbyear = int.Parse(textBox1.Text);
tbmonth = int.Parse(textBox2.Text);
tbpnr = int.Parse(textBox3.Text);
string tby = textBox1.Text;
string tbm = textBox2.Text;
string tbnr = textBox3.Text;
string path = Path.Combine(tby, tbm);
string pathnr = textBox1.Text + textBox2.Text + textBox3.Text;
System.Diagnostics.Process.Start("explorer.exe", #"L:\" + path + "\\" + pathnr);

As a very simple example of text extraction, use Substring.
string textFromInputControl = "20190133";
string year = textFromInputControl.Substring(0, 4); // start at index 0, 4 chars long
string month = textFromInputControl.Substring(4, 2); // start at index 4, 2 chars long
string poNumber = textFromInputControl.Substring(6); // start at index 6, all remaining chars
Console.WriteLine(year); // "2019"
Console.WriteLine(month); // "01"
Console.WriteLine(poNumber); // "33"
There are, of course, more complex ways of doing text extraction, like Regex. Use other tools when they are more appropriate.

I think that it's fine as it is. If you have 3 differents inputs in 3 differents textboxes it's well designed.
Imagine that one day you make a change and you don't want to join these types for generate your path: year\month\projectNumber.
This would implies to change UI + Code. If you keep your input in only 1 text box, the changes only affect to code.

I'm not so sure that entering all three items into one textbox is simpler from a user's perspective, but if you want to do that here's one way:
This assumes that the entries are separated in some way (we'll go with a space character).
var parts = textbox.Text.Split(' ');
var pathToOpen = $#"L:\{parts[0]}\{parts[1]}\{parts[2]}";
The above code splits the contents of the textbox by its ' ' delimiter, then formats them into a path in the format you provided.
Edit: going by the comments, you don't want to have a delimiter. In the case that your first two parts of the path are of fixed length, you can use the Substring method to extract them:
var year = textbox.Text.Substring(0, 4);
var month = textbox.Text.Substring(4, 2);
var rest = textbox.Text.Substring(6);

Get only numbers from line in file

So I have this file with a number that I want to use.
This line is as follows:
TimeAcquired=1433293042
I only want to use the number part, but not the part that explains what it is.
So the output is:
1433293042
I just need the numbers.
Is there any way to do this?

Follow these steps:
read the complete line
split the line at the = character using string.Split()
extract second field of the string array
convert string to integer using int.Parse() or int.TryParse()

There is a very simple way to do this and that is to call Split() on the string and take the last part. Like so if you want to keep it as a string:
var myValue = theLineString.Split('=').Last();
If you need this as an integer:
int myValue = 0;
var numberPart = theLineString.Split('=').Last();
int.TryParse(numberPart, out myValue);

string setting=sr.ReadLine();
int start = setting.IndexOf('=');
setting = setting.Substring(start + 1, setting.Length - start);

A good approach to Extract Numbers Only anywhere they are found would be to:
var MyNumbers = "TimeAcquired=1433293042".Where(x=> char.IsDigit(x)).ToArray();
var NumberString = new String(MyNumbers);
This is good when the FORMAT of the string is not known. For instance you do not know how numbers have been separated from the letters.

you can do it using split() function as given below
string theLineString="your string";
string[] collection=theLineString.Split('=');
so your string gets divided in two parts,
i.e.
1) the part before "="
2) the part after "=".
so thus you can access the part by their index.
if you want to access numeric one then simply do this
string answer=collection[1];

try
string t = "TimeAcquired=1433293042";
t= t.replace("TimeAcquired=",String.empty);
After just parse.
int mrt= int.parse(t);

C# , Substring How to access last elements of an array/string using substring

I am generating 35 strings which have the names ar15220110910, khwm20110910 and so on.
The string contains the name of the Id (ar152,KHWM), and the date (20110910). I want to extract the Id, date from the string and store it in a textfile called StatSummary.
My code statement is something like this
for( int 1= 0;i< filestoextract.count;1++)
{
// The filestoextract contains 35 strings
string extractname = filestoextract(i).ToString();
statSummary.writeline( extractname.substring(0,5) + "" +
extractname.substring(5,4) + "" + extractname.substring(9,2) + "" +
extractname.substring(11,2));
}
When the station has Id containing 5 letters, then this code executes correctly but when the station Id is KHWM or any other 4 letter name then the insertion is all messed up. I am running this inside a loop. So I have tried keeping the code as dynamic as possible. Could anyone help me to find a way without hardcoding it. For instance accessing the last 8 elements to get the date??? I have searched but am not able to find a way to do that.

For the last 8 digits, it's just:
extractname.Substring(extractname.Length-8)
oh, I'm sorry, and so for your code could be:
int l = extractname.Length;
statSummary.WriteLine(extractname.substring(0,l-8) + "" +
extractname.Substring(l-8,4) + "" + extractname.Substring(l-4,2) + "" +
extractname.Substring(l-2,2));

As your ID length isn't consistent, it would probably be a better option to extract the date (which is always going to be 8 chars) and then treat the remainder as your ID e.g.
UPDATED - more robust by actually calculating the length of the date based on the format. Also validates against the format to make sure you have parsed the data correctly.
var dateFormat = "yyyyMMdd"; // this could be pulled from app.config or some other config source
foreach (var file in filestoextract)
{
var dateStr = file.Substring(file.Length-dateFormat.Length);
if (ValidateDate(dateStr, dateFormat))
{
var id = file.Substring(0, file.Length - (dateFormat.Length+1));
// do something with data
}
else
{
// handle invalid filename
}
}
public bool ValidateDate(stirng date, string date_format)
{
try
{
DateTime.ParseExact(date, date_format, DateTimeFormatInfo.InvariantInfo);
}
catch
{
return false;
}
return true;
}

You could use a Regex :
match = Regex.Match ("khwm20110910","(?<code>.*)(?<date>.{6})" );
Console.WriteLine (match.Groups["code"] );
Console.WriteLine (match.Groups["date"] );
To explain the regex pattern (?<code>.*)(?<date>.{6}) the brackets groups creates a group for each pattern. ?<code> names the group so you can reference it easily.
The date group takes the last six characters of the string. . says take any character and {6} says do that six times.
The code group takes all the remaining characters. * says take as many characters as possible.

for each(string part in stringList)
{
int length = part.Length;
int start = length - 8;
string dateString = part.Substring(start, 8);
}
That should solve the variable length to get the date. The rest of the pull is most likely dependent on a pattern (suggested) or the length of string (when x then the call is 4 in length, etc)

If you ID isn't always the same amount of letters you should seperate the ID and the Date using ',' or somthing then you use this:
for( int 1= 0;i< filestoextract.count;1++)
{
string extractname = filestoextract[i].ToString();
string ID = extractname.substring(0, extractname.IndexOf(','));
string Date = extractname.substring(extractname.IndexOf(','));
Console.WriteLine(ID + Date);
}