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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.

C# text file to string array and how to remove specific strings?

I need read a text file (10mb) and convert to .csv. See below portion of code:
string DirPathForm = System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetEntryAssembly().Location);'
string[] lines = File.ReadAllLines(DirPathForm + #"\file.txt");
Some portion of the text file have a pattern. So, used as below:
string[] lines1 = lines.Select(x => x.Replace("abc[", "ab,")).ToArray();
Array.Clear(lines, 0, lines.Length);
lines = lines1.Select(x => x.Replace("] CDE ", ",")).ToArray();
Some portion does not have a pattern to use directly Replace. The question is how remove the characters, numbers and whitespaces in this portion. Please see below?
string[] lines = {
"a] 773 b",
"e] 1597 t",
"z] 0 c"
};
to get the result below:
string[] result = {
"a,b",
"e,t",
"z,c"
};
obs: the items removed need be replaced by ",".

First of all, you should not use ReadAllLines since it is a huge file operation. It will load all the data into RAM and it is not correct. Instead, read the lines one by one in a loop.
Secondly, you can definitely use regex to replace data from the first condition to the second one.

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 to separate values from asp.net textbox with linebreak?

I'm trying to separate the values from an asp.net textbox which ends with line breaks. For example -
959100001
959100002
Those values must be inserted into an array like {95910001, 959100002} to do further calculation.
Any advices?
I'm using C# btw.

string test = "959100001\r\n959100002\r\n";
foreach(var item in test.Split(new char []{'\r','\n'},StringSplitOptions.RemoveEmptyEntries))
Console.WriteLine(item);
Prints:
959100001
959100002
Or as suggested by Mike:
test.Split(new string[]{Environment.NewLine},StringSplitOptions.RemoveEmptyEntries))

You have to use String.split() method which split string based upon newline delimiter and return string[] array. Further you can use long.TryParse or int.TryParse method to convert string to number (int/long) type.

I had tried this in my environment. See below....
My code snippet for your question's answer is below.
string[] lines = txtline.Text.Split(new string[]{Environment.NewLine},StringSplitOptions.RemoveEmptyEntries);
It works fine.....

Not tested:
string[] lines = TextBox1.Text.Split(Environment.NewLine);

if you just want to separate them, you can simply call Split method:
string[] lines = TextBox1.Text.Split('\n', '\r');
if you also want to convert these values to integer, try this:
int[] lines = Array.ConvertAll<string, int>(TextBox1.Text.Split('\n', '\r'), Convert.ToInt32);

cutting from string in C#

My strings look like that: aaa/b/cc/dd/ee . I want to cut first part without a / . How can i do it? I have many strings and they don't have the same length. I tried to use Substring(), but what about / ?
I want to add 'aaa' to the first treeNode, 'b' to the second etc. I know how to add something to treeview, but i don't know how can i receive this parts.

Maybe the Split() method is what you're after?
string value = "aaa/b/cc/dd/ee";
string[] collection = value.Split('/');
Identifies the substrings in this instance that are delimited by one or more characters specified in an array, then places the substrings into a String array.
Based on your updates related to a TreeView (ASP.Net? WinForms?) you can do this:
foreach(string text in collection)
{
TreeNode node = new TreeNode(text);
myTreeView.Nodes.Add(node);
}

Use Substring and IndexOf to find the location of the first /
To get the first part:
// from memory, need to test :)
string output = String.Substring(inputString, 0, inputString.IndexOf("/"));
To just cut the first part:
// from memory, need to test :)
string output = String.Substring(inputString,
inputString.IndexOf("/"),
inputString.Length - inputString.IndexOf("/");

You would probably want to do:
string[] parts = "aaa/b/cc/dd/ee".Split(new char[] { '/' });

Sounds like this is a job for... Regular Expressions!

One way to do it is by using string.Split to split your string into an array, and then string.Join to make whatever parts of the array you want into a new string.
For example:
var parts = input.Split('/');
var processedInput = string.Join("/", parts.Skip(1));
This is a general approach. If you only need to do very specific processing, you can be more efficient with string.IndexOf, for example:
var processedInput = input.Substring(input.IndexOf('/') + 1);