Develop Reference

Can someone please confirm the reason behind foreach loop giving error as "invalid token" and "splittedText" as does not exist in current context?

string[] splittedText = File.ReadAllLines(#"file.txt");//.Split(',');
foreach (string data in splittedText)
{
}
I want to read through a file in c# which returns array of string type. Then, I will be iterating over the array to fetch my desired data.

If you want to read a CSV file, you should use a CVS parser. Values in the CSV file are separated using command and in some cases, the value in the CSV file can also contain a comma. In that case, the column values are wrapped in double-quotes. And this solution will not handle that scenario.
var splittedText = File.ReadAllText("E:\\Test.txt").Split(',');
foreach (string data in splittedText)
{
Console.WriteLine(data.Trim());
}

Hint - Reading file line by line or Reading whole file content depends on your use case. May be below code snippet give some idea on how to split the content.
Please try.
var inputtext = File.ReadAllText(#"inpufile.txt");
inputtext.Replace("\n", "")
.Split(',',
StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries)
.ToList().ForEach(t =>
{
System.Console.WriteLine(t);
//Other manupulations
});
if you want to split based on multiple characters , pass a character array to the split().
new char[] { ',', ':' };
Thank you.

You need change File.ReadAllLines to File.ReadAllText(path) then you can split method.

Use everything before a specific character

So, I've been learning C# and I need to remove everything after the
":" character.
I've used a StreamReader to read the text file, but then I can't use the Split function, then I tried it by using an int function to import it, but then again I can't use the Split function?
What I want this to do is import a text file that's written like;
name:lastname
name2:lastname2
And so that it only shows name and name2.
I've been searching this for a couple of days but I can't seem to figure it out!
I don't know what I'm doing wrong and how to import the text file without using StreamReader or anything else.
Edit:
I'm trying to post something to a website that goes like;
example.com/q=(name without ":")
Edit 2:
StreamReader list = new StreamReader(#"list.txt");
string reader = list.ReadToEnd();
string[] split = reader.Split(":".ToCharArray());
Console.WriteLine(split);
gives output as;
System.String[]

You've got a few issues here. First, use File.ReadLines() instead of a StreamReader, its much simpler and easier:
IEnumerable<string> lines = File.ReadLines("path/to/file");
Next, your lines variable needs to be iterated so you can get to each line of the collection:
foreach (string line in lines)
{
//TODO: write split logic here
}
Then you have to split each line on the ':' character:
string[] split = line.Split(":");
Your split variable is an array of string (i.e string[]) which means you have to access a specific index of the array if you want to see its value. This is your second issue, if you pass split to Console.WriteLine() under the hood it just calls .ToString() on the object you have passed it, and with a string[] it won't automatically give you all the values, you have to write that yourself.
So if your line variable was: "name:Steve", the split variable would have two indexes and look like this:
//split[0] = "name"
//split[1] = "Steve"
I made a fiddle here that demonstrates.

I your file size small and your name:lastname in one line use:
var lines = File.ReadAllLines("filaPath");
foreach (var line in lines)
{
var array = line.Split(':');
if (array.Length > 0)
{
var name = array[0];
}
}
if name:lastname isn't in new line tell me how it's seprated

How can i analise millions of strings that merge into each other?

I have millions of strings, around 8GB worth of HEX; each string is 3.2kb in length.
Each of these strings contains multiple parts of data I need to extract.
This is an example of one such string:
GPGGA,104644.091,,,,,0,0,,,M,,M,,*43$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Test.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ$GPGGA,104645.091,,,,,0,0,,,M,,M,,*42$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Test.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ ÿÿ!ÿÿ"ÿÿ#ÿÿ$ÿÿ%ÿÿ&ÿÿ'ÿÿ(ÿÿ)ÿÿ*ÿÿ+ÿÿ,ÿÿ-ÿÿ.ÿÿ/ÿÿ0ÿÿ1ÿÿ$GPGGA,104646.091,,,,,0,0,,,M,,M,,*41$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Test2ÿÿ3ÿÿ4ÿÿ5ÿÿ6ÿÿ7ÿÿ8ÿÿ9ÿÿ:ÿÿ;ÿÿ<ÿÿ=ÿÿ>ÿÿ?ÿÿ#ÿÿAÿÿBÿÿCÿÿDÿÿEÿÿFÿÿGÿÿHÿÿIÿÿJÿÿ$GPGGA,104647.091,,,,,0,0,,,M,,M,,*40$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header TestKÿÿLÿÿMÿÿNÿÿOÿÿPÿÿQÿÿRÿÿSÿÿTÿÿUÿÿVÿÿWÿÿXÿÿYÿÿZÿÿ[ÿÿ\ÿÿ]ÿÿ^ÿÿ_ÿÿ`ÿÿaÿÿbÿÿcÿÿ$GPGGA,104648.091,,,,,0,0,,,M,,M,,*4F$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Testdÿÿeÿÿfÿÿgÿÿhÿÿiÿÿjÿÿkÿÿlÿÿmÿÿnÿÿoÿÿpÿÿqÿÿrÿÿsÿÿtÿÿuÿÿvÿÿwÿÿxÿÿyÿÿzÿÿ{ÿÿ|ÿÿ$GPGGA,104649.091,,,,,0,0,,,M,,M,,*4E$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Test}ÿÿ~ÿÿ.ÿÿ€ÿÿ.ÿÿ‚ÿÿƒÿÿ„ÿÿ…ÿÿ†ÿÿ‡ÿÿˆÿÿ‰ÿÿŠÿÿ‹ÿÿŒÿÿ.ÿÿŽÿÿ.ÿÿ.ÿÿ‘ÿÿ’ÿÿ“ÿÿ”ÿÿ•ÿÿ$GPGGA,104650.091,,,,,0,0,,,M,,M,,*46$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Head
as you can see it is pretty much this repeated:
GPGGA,104644.091,,,,,0,0,,,M,,M,,*43$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Test.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ$GPGGA,104645.091,,,,,0,0,,,M,,M,,*42$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32Header Test.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ ÿÿ!ÿÿ"ÿÿ#ÿÿ$ÿÿ%ÿÿ&ÿÿ'ÿÿ(ÿÿ)ÿÿ*ÿÿ+ÿÿ,ÿÿ-ÿÿ.ÿÿ/ÿÿ0ÿÿ1ÿÿ
I want to separate this string into two lists like this:
_GPSList
$GPGGA,104644.091,,,,,0,0,,,M,,M,,*43
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N
_WavList
32HeaderTest.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ
32HeaderTest.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ.ÿÿ ÿÿ!ÿÿ"ÿÿ#ÿÿ$ÿÿ%ÿÿ&ÿÿ'ÿÿ(ÿÿ)ÿÿ*ÿÿ+ÿÿ,ÿÿ-ÿÿ.ÿÿ/ÿÿ0ÿÿ1ÿÿ
Issue 1:
This repetition isn't containing within a single string, it overflows into the next string. so if some data crosses the end and start of two strings how to I deal with that?
Issue 2: How do I analyse the string and extract only the parts I need?

The solution I'm providing is not a complete answer but more like an idea which might help you get what you want.
Everything else which I present is an assumption on my behalf.
//Assuming your data is stored in a file "yourdatafile"
//Splitting all the text on "$" assuming this will separate GPSData
string[] splittedstring = File.ReadAllText("yourdatafile").Split('$');
//I found an extra string lingering in the sample you provided
//because I splitted on "$", so you gotta take that into account
var GPSList = new List<string>();
var WAVList = new List<string>();
foreach (var str in splittedstring)
{
//So if the string contains "Header" we would want to separate it from GPS data
if (str.Contains("Header"))
{
string temp = str.Remove(str.IndexOf("Header"));
int indexOfAsterisk = temp.LastIndexOf("*");
string stringBeforeAsterisk = str.Substring(0, indexOfAsterisk + 1);
string stringAfterAsterisk = str.Replace(stringBeforeAsterisk, "");
WAVList.Add(stringAfterAsterisk);
GPSList.Add("$" + stringBeforeAsterisk);
}
else
GPSList.Add("$" + str);
}
This provides the exact output as you need, only exception is with that extra string. Also some non-standard characters might look like black blocks.

string.Split ignores Null values between delimiters

I'm trying to convert some data into sql statements with the use of Streamreader and Streamwriter.
My problem is, when i split lines which in which between 2 delimiters is nothing, not even a space, they get ignored and i get a IndexOutOfRange error
because my temparray only goes till temparray[3] , but it should go to like temparray[6] ..
How can i split and use Null values or replace those null values with a simple char, so that i dont get an IndexOutOfRange error when i want to create my sql statements ?
foreach (string a in values)
{
int temp = 1;
String[] temparray = a.Split(';');
streamWriter.WriteLine("Insert into table Firma values({0},'{1}','{2}')", temp, temparray[1], temparray[4]);
temp++;
}

First of all, this is asking for trouble (SQL injection). You should at the very least escape the values parsed from the string.
And you seem to be mistaken, as String.Split does exactly what you want by default: "x;y;;z".Split(';') returns a four-element array {"x", "y", "", "z"}. You can achieve the described behavior by using StringSplitOptions.RemoveEmptyEntries: "x;y;;z".Split(new[] {';'}, StringSplitOptions.RemoveEmptyEntries) returns a three-element array {"x", "y", "z"}. Which is what you do not want, as you say.
Either way, "Überarbeitung der SAV Seite;b.i.b.;;;;PB;".Split(';') returns a seven-element array here for me, so check your inputs and implementation…

If you print out your string, I'm pretty sure it will not be what you expect it to be.
static void Main(string[] args)
{
var result = "Überarbeitung der SAV Seite;b.i.b.;;;;PB;".Split(';');
foreach (var part in result)
{
Console.WriteLine(" --> " + part);
}
Console.ReadLine();
}
This works great. It will not ignore the empty values. It will print
--> Überarbeitung der SAV Seite
--> b.i.b.
-->
-->
-->
--> PB
-->
including the empty values.
Greetings to bib Paderborn :)

If you're using SQL Server, you can return empty strings instead of null by using the ISNULL operator in your query.
For example:
SELECT ISNULL(PR_Arbeitstitel, '') FROM Table

Why don't you iterate over your temparray to build up a string of param values.
This is by no means perfect, but should point you in the direction
foreach (string a in values)
{
int temp = 1;
String[] temparray = a.Split(';');
var stringBuilder = new StringBuilder();
foreach (var s in temparray)
stringBuilder.Append("'" + s + "',");
var insertStatement = string.Format("Insert into table Firma values({0}, {1})", temp, stringBuilder.ToString().TrimEnd(','));
temp++;
}

Why would you have 2 delimiters in a row with nothing inbetween them? Do you not control the input?
In that case you could control it by inserting a so-called sentinel value, such as "IGNOREMEPLEASE":
String[] temparray = a.Replace(";;", ";IGNOREMEPLEASE;").Split(';');
Then the rest of your code knows that IGNOREMEPLEASE means there was an empty line, and it should be ignored.
That being said, be very careful about what you send to a database, and scrub incoming data that you use to build SQL statements with, to get rid of anything dangerous.

I don't see your issue occurring. The following outputs a string.Empty for string[2] and has all 5 elements
string[] str = "0,1,,3,4".Split(new char[] { ',' });
foreach (string s in str)
{
Debug.Print(s);
}
output
0
1
3
4

I've tried to reproduce with your example of string "Überarbeitung der SAV Seite;b.i.b.;;;;PB;" but everything was fine. I've got 7 items in array.
You can try to use
string s = "Überarbeitung der SAV Seite;b.i.b.;;;;PB;";
var result = s.Split(new[] { ';' }, StringSplitOptions.None);
To be sure that StringSplitOptions.RemoveEmptyEntries is not enabled.

Perhaps use the ?? operator:
streamWriter.WriteLine(
"Insert into table Firma values({0},'{1}','{2}')",
temp,
temparray[1] ?? 'x',
temparray[4] ?? 'x');
This still is only safe, though, if you know for sure that your input has at least 5 tokens after splitting. If you can't guarantee this you'll need to wrap it in a conditional:
if (temparray.Length < 5)
{
// handle invalid input
}

Loop Problem: Assign data to different strings when in a loop

I have a string which consists of different fields. So what I want to do is get the different text and assign each of them into a field.
ex: Hello Allan IBM
so what I want to do is:
put these three words in different strings like
string Greeting = "Hello"
string Name = "Allan"
string Company = "IBM"
//all of it happening in a loop.
string data = "Hello Allan IBM"
string s = data[i].ToString();
string[] words = s.Split(',');
foreach (string word in words) {
Console.WriteLine(word);
}
any suggestions?
thanks hope to hear from you soon

If I understand correctly you have a string with place-holders and you want to put different string in those place-holders:
var format="{0}, {1} {2}. How are you?";
//string Greeting = "Hello"
//string Name = "Allan"
//string Company = "IBM"
//all of it happening in a loop.
string data = ...; //I think you have an array of strings separated by ,
foreach( va s in data){
{
//string s = data[i];//.ToString(); - it is already a string array
string[] words = data[i].Split(',');
Console.WriteLine(format, words[0], words[1], words[2]);
}

To me it sound not like a problem that can be solved with a loop. The essential problem is that the loop can only work if you do exactly the same operation on the items within the loop. If your problem doesn't fit, you end up with a dozen of lines of code within the loop to handle special cases, what could have been written in a shorter way without a loop.
If there are only two or three strings you have to set (what should be the case if you have named variables), assign them from the indexes of the split string. An alternative would be using regular expressions to match some patterns to make it more robust, if one of the expected strings is missing.
Another possibility would be to set attributes on members or properties like:
[MyParseAttribute(/*position*/ /*regex*/)]
string Greeting {get;set;}
And use reflexion to populate them. Here you could create a loop on all properties having that attribute, as it sounds to me that you are eager to create a loop :-)