C# only use arrays if it exists - c#
I am a beginner in programming. And now I'm facing a task where I can't get any further. Probably it is relatively easy to solve.
This is what I want to do: I read out a .txt file and there are several lines of content.
Example what is in the .txt file:
text1,text2,text3
text1,text2,
text1,text2,text3,text4
I'm now ready to find the right line and use it. Then I want to split the line and assign each text to its own string.
I can do this if I know that this line have 4 words. But what if I don't know how many words this line have.
For example if I want to assign 5 strings but there are only 4 arrays in the column I get an error.
My program currently looks like this:
string reader = "text1,text2,text3,text4";
string[] words = reader.Split(',');
string word1 = words[0].ToString();
string word2 = words[1].ToString();
string word3 = words[2].ToString();
string word4 = words[3].ToString();
textBox1.Text = word3;
My goal is to find out how many words are in the string. And then pass each word to a separate string.
Thank you in advance
To get the length of the Array, you can easily use .Length
In your example, you just write
int arraylength = words.Length;
I don't understand, why do you want to create a new String for every value of the string-array? You can just use them in the array.
In your example you always user .ToString(), this isn't necessary because you already have a string.
An array is just multiple variables (in your example strings) which are connected to another.
I doubt if you want separated local variables like word1, word2 etc. To see why, let's
bring the idea to the point of absurdity. Imagine, that we have a small narration with 1234
words only. Do we really want to create word1, word2, ..., word1234 local variables?
So, let's stick to a single words array only:
string[] words = reader.Split(',');
Now, you can easily get array Length (i.e. number of items):
textBoxCount.Text = $"We have {words.Length} words in total";
Or get N-th word (let N be one based) from the words array:
string wordN = array.Length >= N ? array[N - 1] : "SomeDefaultValue";
In your case (3d word) it can be
// either 3d word or an empty string (when we have just two less words)
textBox1.Text = array.Length >= 3 ? array[3 - 1] : "";
Technically, you can use Linq and query the reader string:
using System.Linq;
...
// 3d word or empty string
textBox1.Text = reader.Split(',').ElementAtOrDefault(3 - 1) ?? "";
But Linq seems to be overshot here.
Related
How can i analise millions of strings that merge into each other?
I have millions of strings, around 8GB worth of HEX; each string is 3.2kb in length.
Each of these strings contains multiple parts of data I need to extract.
This is an example of one such string:
GPGGA,104644.091,,,,,0,0,,,M,,M,,*43$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.
how to get text after a certain comma on C#?
Ok guys so I've got this issue that is driving me nuts, lets say that I've got a string like this "aaa,bbb,ccc,ddd,eee,fff,ggg" (with out the double quotes) and all that I want to get is a sub-string from it, something like "ddd,eee,fff,ggg". I also have to say that there's a lot of information and not all the strings look the same so i kind off need something generic. thank you!
One way using split with a limit;
string str = "aaa,bbb,ccc,ddd,eee,fff,ggg";
int skip = 3;
string result = str.Split(new[] { ',' }, skip + 1)[skip];
// = "ddd,eee,fff,ggg"
I would use stringToSplit.Split(',')
Update:
var startComma = 3;
var value = string.Join(",", stringToSplit.Split(',').Where((token, index) => index > startComma));
Not really sure if all things between the commas are 3 length. If they are I would use choice 2. If they are all different, choice 1. A third choice would be choice 2 but implement .IndexOf(",") several times.
Two choices:
string yourString="aaa,bbb,ccc,ddd,eee,fff,ggg";
string[] partsOfString=yourString.Split(','); //Gives you an array were partsOfString[0] is "aaa" and partsOfString[1] is "bbb"
string trimmed=partsOfString[3]+","+partsOfString[4]+","+partsOfString[5]+","+partsOfSting[6];
OR
//Prints "ddd,eee,fff,ggg"
string trimmed=yourString.Substring(12,14) //Gets the 12th character of your string and goes 14 more characters.
Clip string inside of Array
Lets say I have a String Array full of items such as:
string[] letters = new string[4] {"A1","B1","C1","D1"};
Later, I want to set the contents of a textbox to the first value in the array:
Letter.Content = letters[0];
Is there a way to 'clip' the number out of the String in the Array? For example, in my above code, currently the Letter textbox would be set to 'A1'. What I want however is to set it to just 'A'.
Depends on if the strings's length is always two and the digit is at the second position. Then it's simple: Letter.Content = letters[0][0]; If you don't know the length but you want to take all letters from the left until there is a non-letter you could use string.Concat + LINQ: Letter.Content = string.Concat(letters[0].TakeWhile(Char.IsLetter));
or you could do it the old fashion way using SubString Method Letter.Content = letters[0].Substring(0,1);
Calculating number of words from input text
I split the input paragraph by . and store it in an array like this:
string[] totalSentences = inputPara.Split('.')
then the function below is called which calculates total number of Words from each sentence like this:
public void initParaMatrix()
{
int size = 0;
for (int i = 0; i < totalSentences.Length; i++)
{
string[] words = totalSentences[i].Split();
size = size + words.Length;
//rest of the logic here...
}
matrixSize = size;
paraMatrix = new string[matrixSize, matrixSize];
}
paraMatrix is a 2D matrix equal to length of all words which I need to make in my logic.
The problem here is when I input only one sentence which has 5 words, the size variable gets the value 7. I tried the debugger and I was getting total of 2 sentences instead of 1.
Sentence 1. "Our present ideas about motion." > this is actual sentence which have only 5 words
Sentence 2. " " > this is the exact second sentence I'm getting.
Here is the screenshot:
Why I'm getting two sentences here and how is size getting value 7?
This makes perfect sense. If the second sentence has nothing but a " ", and you split along the " ", then you'll have two empty strings as a result. The easiest thing to do here is change the line you do the split, and add a trim: string[] words = totalSentences[i].Trim().Split(); I don't know what version of Split that you're using since it accepts no parameters, but if you use String.Split you can set the second parameter so that empty entries are automatically removed by using the option StringSplitOptions.RemoveEmptyEntries.
You're not resetting the size integer to zero. So that's why you get 7 for the second sentence. For the second sentence, which is a space, try inputPara.Trim() which should remove the space at the end of the string.
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);