Using RemoveEmptryEntries with .Split in C# - c#

I have a string that's using semicolons as the delimitor. I drop them into a List of strings, and I want it to ignore Empty entries, but the option is throwing an error when I include it. The working code looks like so:
tContent = (HtmlInputText)FindControl("SomeInput");
string tText = tContent.Value;
List<string> tTextList = tText.Split(';').ToList();
To get rid of extra blank entries, I tried to employ this:
tContent = (HtmlInputText)FindControl("SomeInput");
string tText = tContent.Value;
List<string> tTextList = tText.Split(';', StringSplitOptions.RemoveEmptyEntries).ToList();
But it comes back with an error that it contains invalid arguments. My best efforts seem to indicate that this should be valid, but the compiler disagrees. I suspect a very silly error and I'm just in need of a second set of eyes in this case.

Change
List<string> tTextList = tText.Split(';', StringSplitOptions.RemoveEmptyEntries).ToList();
to
List<string> tTextList = tText.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries)
You can see the supported signatures for string.Split here: http://msdn.microsoft.com/en-us/library/system.string.split(v=vs.110).aspx

You need a char array:
List<string> tTextList = tText.Split(new char[]{';'}, StringSplitOptions.RemoveEmptyEntries).ToList();

Related

Get a string inside a string

string a = "100-0-6-7-6-10-8-" //and so on
/////////////////////////////////////////////
//my solution
char[] delimiterChars = {'-'};
string solution = "100-0-6-7-6-10-8-";
string[] words = solution.Split(delimiterChars,System.StringSplitOptions.RemoveEmptyEntries);
//ok so i encounter some problems when trying to overwrite 0s, and 10s,100s etc
//so when writing data to the "solution" string it should be
//"-100--0--6--7--6--10--8-" instead of "100-0-6-7-6-10-8-"
basically, I want to separate each number and put it in a list or array
i think i got it
char[] delimiterChars = {'-'};
string text = "100-0-6-7-6-10-8-";
string[] words = text.Split(delimiterChars,System.StringSplitOptions.RemoveEmptyEntries);
This solution using Linq works as well.
var text="100-0-6-7-6-10-8-";
var words=text.Split("-").Where(x => !string.IsNullOrEmpty(x)).ToArray();

Why does this bit of C# code with array initializer not refactor how I expect

I have the following code;
char[] leadingDot = { '.' };
string trimStart = fileName.TrimStart(leadingDot);
I cannot seem to figure out the syntax to combine it into a single line. ReSharper has no suggestions either.
I completely understand why the following code doesn't work, let alone look right, but I would expect something like:
string trimStart = fileName.TrimStart( { '.' } );
It gives me the same vibe you get when you type var x = null; Ideas?
string trimStart = fileName.TrimStart(new char[] { '.'});

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);
}

remove first element from array

PHP developer here working with c#.
I'm using a technique to remove a block of text from a large string by exploding the string into an array and then shifting the first element out of the array and turning what remains back into a string.
With PHP (an awesome & easy language) it was just
$array = explode('somestring',$string);
array_shift($array);
$newstring = implode(' ', $array);
and I'm done.
I get so mad at c# for not allowing me to create dynamic arrays and for not offering me default functions that can do the same thing as PHP regarding arrays. Instead of dynamic arrays I have to create lists and predefine key structures etc. But I'm new and I'm sure there are still equally graceful ways to do the same with c#.
Will someone show me a clean way to accomplish this goal with c#?
Rephrase of question: How can I remove the first element from an array using c# code.
Here is how far I've gotten, but RemoveAt throws a error while debugging so I don't believe it works:
//scoop-out feed header information
if (entry_start != "")
{
string[] parts = Regex.Split(this_string, #entry_start);
parts.RemoveAt(0);
this_string = String.Join(" ", parts);
}
I get so mad at c# for not allowing me to create dynamic arrays
You may take a look at the List<T> class. Its RemoveAt might be worth checking.
But for your particular scenario you could simply use LINQ and the Skip extension method (don't forget to add using System.Linq; to your file in order to bring it into scope):
if (entry_start != "")
{
string[] parts = Regex.Split(this_string, #entry_start).Skip(1).ToArray();
this_string = String.Join(" ", parts);
}
C# is not designed to be quick and dirty, nor it particularly specializes in text manipulation. Furthermore, the technique you use for removing some portion of a string from a beginning is crazy imho.
Why don't you just use String.Substring(int start, int length) coupled with String.IndexOf("your delimiter")?
Here is the corresponding C# code:
string input = "a,b,c,d,e";
string[] splitvals = input.Split(',');
string output = String.Join(",", splitvals, 1, splitvals.Length-1);
MessageBox.Show(output);
You can use LINQ for this:
if (entry_start != "")
this_string = String.Join(" ", Regex.Split(this_string, #entry_start).Skip(1).ToArray());
string split = ",";
string str = "asd1,asd2,asd3,asd4,asd5";
string[] ary = str.Split(new string[] { split }, StringSplitOptions.RemoveEmptyEntries);
string newstr = string.Join(split, ary, 1, ary.Count() - 1);
splits at ",". removes the first record. then combines back with ","
As stated above, you can use LINQ. Skip(int) will return an IEnumerable<string> that you can then cast back as array.
string[] myArray = new string[]{"this", "is", "an", "array"};
myArray = myArray.Skip(1).toArray();
You might be more comfortable with generic lists than arrays, which work more like PHP arrays.
List<T>
But if your goal is "to remove a block of text from a large string" then the easier way would be:
string Example = "somestring";
string BlockRemoved = Example.Substring(1);
// BlockRemoved = "omestring"
Edit
I misunderstood the question, thinking you were just removing the first element from the array where the array consisted of the characters that make up the string.
To split a string by a delimiter, look at the String.Split method instead. Some good examples are given here.

string[] management

ok, so ill cut to the chase here. and to be clear, im looking for code examples where possible.
so, i have a normal string, lets say,
string mystring = "this is my string i want to use";
ok, now that i have my string, i split it by the space with
string[] splitArray = mystring.Split(new char[] { ' ' });
ok, so now i have splitArray[0] through splitArray[7].
now, i need to do some fancy things with the string that i normally wouldnt need to do.
here are a few:
i need to cut off the first word, so i am left with the other 7 words, so that i have something like:
string myfirstword = "this";
mystring = "is my string i want to use";
now, i will need to use mystring over and over again, using different parts of it at different times, and depending on the string i will have no idea how long, it will be. so i will give some examples of things ill need.
first, ill need to know, how many words are there (this is easy, just throwing it in)
second, ill need some way of using things like,
string secondword = splitArray[1];
string everythingAfterTheSecondWord = splitArray[2+];
if you noticed, i included a [2+] ... the + indicating that i want all strings in the array put back together, spaces in all, into a string. so for example,
string examplestring = "this is my example for my stack overflow question";
string[] splitArray2 = examplestring.Split(new char[] { ' ' });
now, if i called on splitArray2[4+] i would want a return of "for my stack overflow question". now obviously its not as simple as adding a + to a string array.. but thats what i need, and under the current situation i have tried many other easier ways that simply to not work.
ALSO, if i called on something like splitArray2[2-5] i would want, words 2 through 5 obviously.
Summary:
i need greater management of my string[] arrays, and i need to be able to find, every word after word *, need to be able to strip out random words in the string while leaving the rest of the string intact, and need to be able to find string m through n
Thanks!
Most of what you're looking for can be achieved with a List<string>. Briefly:
string mystring = "this is my string i want to use";
List<string> splitArray = new List<string>(mystring.Split(new char[] { ' ' }));
string firstWord = splitArray[0];
// mystring2 = "is my string i want to use"
splitArray.RemoveAt(0);
string mystring2 = String.Join(" ", splitArray.ToArray());
To do the more complicated things you describe with splitArray[2+] requires LINQ though, and hence .NET 3.5.
List<string> everythingAfterTheSecondWord = splitArray.Skip(2).ToList();
For splitArray[2-5]:
List<string> arraySlice = splitArray.Skip(2).Take(3).ToList();
Well, to do the "every word starting at word X" you could do this:
string newString = string.join(splitArray," ",x);
To get y words starting at x, do this:
string newString = string.join(splitArray," ",x,y);
To get the number of words:
int wordCount= splitArray.Length;
Putting it all together, words x-y goes like this:
string newString = string.join(splitArray," ",x, splitArray.Length-x+1);

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