Develop Reference

C# Array Different indexes

Hi i want to search for character in a string array but i need to search Between 2 indices. For example between index 2 and 10. How can I do that?
foreach (var item in currentline[2 to 10])
{
if (item == ',' || item == ';')
{
c++;
break;
}
else
{
data += item;
c++;
}
}

As you can see, foreach enumerates over a collection or any IEnumerable.
As the comments say, you can use a for loop instead, and pick out the elements you want.
Alternatively, since you want to search for a character in a string, you can use IndexOf, using the start index and count overload to find where a character is.

As there is no use of the c++ in your code I will assume that it's a vestige of code.
You can simply addess your issue like this:
In the currentline
Take char from index 2 to 10
Till you find a char you don't want.
concatenate the resulting char array to a string.
Resulting Code:
var data = "##";//01234567891 -- index for the string below.
var currentline= "kj[abcabc;z]Selected data will be between: '[]';";
var exceptChar = ",;";
data += new string(
input.Skip(3)
.Take(8)
.TakeWhile(x=> !exceptChar.Contains(x))
.ToArray()
);

There is a string method called string.IndexOfAny() which will allow you to pass an array of characters to search for, a start index and a count. For your example, you would use it like so:
string currentLine = ",;abcde;,abc";
int index = currentLine.IndexOfAny(new[] {',', ';'}, 2, 10-2);
Console.WriteLine(index);
Note that the last parameter is the count of characters to search starting at the specified index, so if you want to start at index 2 and finish at index 10, the count will be finish-start, i.e. 10-2.

You can search for characters in strings and get their indexes with this LINQ solution:
string str = "How; are, you; Good ,bye";
char[] charArr = { ',', ';' };
int startIndex = 2;
int endIndex = 10;
var indexes = Enumerable.Range(startIndex, endIndex - startIndex + 1)
.Where(i=>charArr.Contains(str[i]))
.ToArray();
In this case we get Enumerable.Range(2, 9) which generates a sequence between 2 and 10 and the Where clause filters the indexes of the characters in str that are matching one of the characters inside charArr.

Thanks everey one finaly i fixed it by your guid thanks all
myarr = new mytable[50];
number_of_records = 0;
number_of_records = fulllines.Length;
for (int line = 1; line < fulllines.Length; line++)
{
int c = 0;
for (int i = 0; i < record_lenth; i++)
{
string data = "";
string currentline = fulllines[line];
string value = "";
for (int x = c; x < fulllines[line].Length; x++)
{
value += currentline[x];
}
foreach (var item in value)
{
if (item == ',' || item == ';')
{
c++;
break;
}
else
{
data += item;
c++;
}
}
}
}

Having trouble finding the start of a sentence inside string array

I have a text file from which I read the text in lines. Also from all that text I need to find the longest sentence and find in which line it begins. I have no trouble finding the longest sentence but the problem arises when I need to find where it begins.
The contents of the text file is:
V. M. Putinas
Margi sakalai
Lydėdami gęstančią žarą vėlai
Pakilo į dangų;;, margi sakalai.
Paniekinę žemės vylingus sapnus,
Padangėje ištiesė,,; savo sparnus.
Ir tarė margieji: negrįšim į žemę,
Kol josios kalnai ir pakalnės aptemę.
My code:
static void Sakiniai (string fv, string skyrikliai)
{
char[] skyrikliaiSak = { '.', '!', '?' };
string naujas = "";
string[] lines = File.ReadAllLines(fv, Encoding.GetEncoding(1257));
foreach (string line in lines)
{
// Add lines into a string so I can separate them into sentences
naujas += line;
}
// Separating into sentences
string[] sakiniai = naujas.Split(skyrikliaiSak);
// This method finds the longest sentence
string ilgiausiasSak = RastiIlgiausiaSakini(sakiniai);
}
From the text file the longest sentence is: "Margi sakalai Lydėdami gęstančią žarą vėlai Pakilo į dangų;;, margi sakalai"
How can I find the exact line where the sentence begins?

What about a nested for loop? If two sentences are the same length, this just finds the first one.
var lines = File.ReadAllLines(fv, Encoding.GetEncoding(1257));
var terminators = new HashSet<char> { '.', '?', '!' };
var currentLength = 0;
var currentSentence = new StringBuilder();
var maxLength = 0;
var maxLine = default(int?);
var maxSentence = "";
for (var currentLine = 0; currentLine < lines.Count(); currentLine++)
{
foreach (var character in lines[currentLine])
{
if (terminators.Contains(character))
{
if (currentLength > maxLength)
{
maxLength = currentLength;
maxLine = currentLine;
maxSentence = currentSentence.ToString();
}
currentLength = 0;
currentSentence.Clear();
}
else
{
currentLength++;
currentSentence.Append(character);
}
}
}

First find the start index of the longest sentence in the whole content
int startIdx = naujas.IndexOf(ilgiausiasSak);
then loop the lines to find out which line the startIdx falls in
int i = 0;
while (i < lines.Length && startIdx >= 0)
{
startIdx -= lines[i].Length;
i++;
}
// do stuff with i
i is where the longest sentence starts at. e.g. i=2 means it start from the second line

Build an index that solves your problem.
We can make a straightforward modification of your existing code:
var lineOffsets = new List<int>();
lineOffsets.Add(0);
foreach (string line in lines)
{
// Add lines into a string so I can separate them into sentences
naujas += line;
lineOffsets.Add(naujas.Length);
}
All right; now you have a list of the character offset in your final string corresponding to each line.
You have a substring of the big string. You can use IndexOf to find the offset of the substring in the big string. Then you can search through the list to find the list index of the last element that is smaller or equal than the offset. That's the line number.
If the list is large, you can binary search it.

How about
identify the lines in the text
split the text into sentences
split the sentences into sections based on the line breaks (could work also with splitting on words as well if needed)
verify the sections of the sentence are on consecutive rows
In the end certain sections of the sentence might occur on multiple lines forming other sentences so you need to correctly identify the sentences spreading consecutive rows
// define separators for various contexts
var separator = new
{
Lines = new[] { '\n' },
Sentences = new[] { '.', '!', '?' },
Sections = new[] { '\n' },
};
// isolate the lines and their corresponding number
var lines = paragraph
.Split(separator.Lines, StringSplitOptions.RemoveEmptyEntries)
.Select((text, number) => new
{
Number = number += 1,
Text = text,
})
.ToList();
// isolate the sentences with corresponding sections and line numbers
var sentences = paragraph
.Split(separator.Sentences, StringSplitOptions.RemoveEmptyEntries)
.Select(sentence => sentence.Trim())
.Select(sentence => new
{
Text = sentence,
Length = sentence.Length,
Sections = sentence
.Split(separator.Sections)
.Select((section, index) => new
{
Index = index,
Text = section,
Lines = lines
.Where(line => line.Text.Contains(section))
.Select(line => line.Number)
})
.OrderBy(section => section.Index)
})
.OrderByDescending(p => p.Length)
.ToList();
// build the possible combinations of sections within a sentence
// and filter only those that are on consecutive lines
var results = from sentence in sentences
let occurences = sentence.Sections
.Select(p => p.Lines)
.Cartesian()
.Where(p => p.Consecutive())
.SelectMany(p => p)
select new
{
Text = sentence.Text,
Length = sentence.Length,
Lines = occurences,
};
and the end results would look like this
where .Cartesian and .Consecutive are just some helper extension methods over enumerable (see associated gist for the entire source code in linqpad ready format)
public static IEnumerable<T> Yield<T>(this T instance)
{
yield return instance;
}
public static IEnumerable<IEnumerable<T>> Cartesian<T>(this IEnumerable<IEnumerable<T>> instance)
{
var seed = Enumerable.Empty<T>().Yield();
return instance.Aggregate(seed, (accumulator, sequence) =>
{
var results = from vector in accumulator
from item in sequence
select vector.Concat(new[]
{
item
});
return results;
});
}
public static bool Consecutive(this IEnumerable<int> instance)
{
var distinct = instance.Distinct().ToList();
return distinct
.Zip(distinct.Skip(1), (a, b) => a + 1 == b)
.All(p => p);
}

Split string into multiple smaller strings

I have a multiline textbox that contains 10 digit mobile numbers separated by comma. I need to achieve string in group of at least 100 mobile numbers.
100 mobile numbers will be separated by 99 comma in total. What i am trying to code is to split the strings containing commas less than 100
public static IEnumerable<string> SplitByLength(this string str, int maxLength)
{
for (int index = 0; index < str.Length; index += maxLength) {
yield return str.Substring(index, Math.Min(maxLength, str.Length - index));
}
}
By using above code, I can achieve 100 numbers as 100 numbers will have 10*100(for mobile number)+99(for comma) text length. But the problem here is user may enter wrong mobile number like 9 digits or even 11 digits.
Can anyone guide me on how can I achieve this.
Thank you in advance.

You could use this extension method to put them into max-100 number groups:
public static IEnumerable<string[]> SplitByLength(this string str, string[] splitBy, StringSplitOptions options, int maxLength = int.MaxValue)
{
var allTokens = str.Split(splitBy, options);
for (int index = 0; index < allTokens.Length; index += maxLength)
{
int length = Math.Min(maxLength, allTokens.Length - index);
string[] part = new string[length];
Array.Copy(allTokens, index, part, 0, length);
yield return part;
}
}
Sample:
string text = string.Join(",", Enumerable.Range(0, 1111).Select(i => "123456789"));
var phoneNumbersIn100Groups = text.SplitByLength(new[] { "," }, StringSplitOptions.None, 100);
foreach (string[] part in phoneNumbersIn100Groups)
{
Assert.IsTrue(part.Length <= 100);
Console.WriteLine(String.Join("|", part));
}

You have a few options,
Put some kind of mask on the input data to prevent the user entering invalid data. In your UI you could then flag the error and prompt the user to reenter correct information. If you go down this route then something like this string[] nums = numbers.Split(','); will be fine.
Alternatively, you could use regex.split or regex.match and match on the pattern. Something like this should work assuming your numbers are in a string with a leading comma or space
Regex regex = new Regex("(\s|,)\d{10},)";
string[] nums = regex.Split(numbers);

This be can resolved with a simple Linq code
public static IEnumerable<string> SplitByLength(this string input, int groupSize)
{
// First split the input to the comma.
// this will give us an array of all single numbers
string[] numbers = input.Split(',');
// Now loop over this array in groupSize blocks
for (int index = 0; index < numbers.Length; index+=groupSize)
{
// Skip numbers from the starting position and
// take the following groupSize numbers,
// join them in a string comma separated and return
yield return string.Join(",", numbers.Skip(index).Take(groupSize));
}
}

SubString editing

I've tried a few different methods and none of them work correctly so I'm just looking for someone to straight out show me how to do it . I want my application to read in a file based on an OpenFileDialog.
When the file is read in I want to go through it and and run this function which uses Linq to insert the data into my DB.
objSqlCommands.sqlCommandInsertorUpdate
However I want to go through the string , counting the number of ","'s found . when the number reaches four I want to only take the characters encountered until the next "," and do this until the end of the file .. can someone show me how to do this ?
Based on the answers given here my code now looks like this
string fileText = File.ReadAllText(ofd.FileName).Replace(Environment.NewLine, ",");
int counter = 0;
int idx = 0;
List<string> foo = new List<string>();
foreach (char c in fileText.ToArray())
{
idx++;
if (c == ',')
{
counter++;
}
if (counter == 4)
{
string x = fileText.Substring(idx);
foo.Add(fileText.Substring(idx, x.IndexOf(',')));
counter = 0;
}
}
foreach (string s in foo)
{
objSqlCommands.sqlCommandInsertorUpdate("INSERT", s);//laClient[0]);
}
However I am getting an "length cannot be less than 0" error on the foo.add function call , any ideas ?

A Somewhat hacky example. You would pass this the entire text from your file as a single string.
string str = "1,2,3,4,i am some text,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20";
int counter = 0;
int idx = 0;
List<string> foo = new List<string>();
foreach (char c in str.ToArray())
{
idx++;
if (c == ',')
{
counter++;
}
if (counter == 4)
{
string x = str.Substring(idx);
foo.Add(str.Substring(idx, x.IndexOf(',')));
counter = 0;
}
}
foreach(string s in foo)
{
Console.WriteLine(s);
}
Console.Read();
Prints:
i am some text
9
13
17

As Raidri indicates in his answer, String.Split is definitely your friend. To catch every fifth word, you could try something like this (not tested):
string fileText = File.ReadAllText(OpenDialog.FileName).Replace(Environment.NewLine, ",");
string words[] = fileText.Split(',');
List<string> everFifthWord = new List<string>();
for (int i = 4; i <= words.Length - 1, i + 5)
{
everyFifthWord.Add(words[i]);
}
The above code reads the selected file from the OpenFileDialog, then replaces every newline with a ",". Then it splits the string on ",", and starting with the fifth word takes every fifth word in the string and adds it to the list.

File.ReadAllText reads a text file to a string and Split turns that string into an array seperated at the commas:
File.ReadAllText(OpenDialog.FileName).Split(',')[4]
If you have more than one line use:
File.ReadAllLines(OpenDialog.FileName).Select(l => l.Split(',')[4])
This gives an IEnumerable<string> where each string contains the wanted part from one line of the file

It's not clear to me if you're after every fifth piece of text between the commas or if there are multiple lines and you want only the fifth piece of text on each line. So I've done both.
Every fifth piece of text:
var text = "1,2,3,4,i am some text,6,7,8,9"
+ ",10,11,12,13,14,15,16,17,18,19,20";
var everyFifth =
text
.Split(',')
.Where((x, n) => n % 5 == 4);
Only the fifth piece of text on each line:
var lines = new []
{
"1,2,3,4,i am some text,6,7",
"8,9,10,11,12,13,14,15",
"16,17,18,19,20",
};
var fifthOnEachLine =
lines
.Select(x => x.Split(',')[4]);

String to array

I have a string :
id0:xxxxx:id0-value:xxxxx:id1:xxxxxxxx:id1-value:xxxxx:id3:xxxxxxxx:id3-value:xxx
I just need the value for idX-value from the string into array.
How can I achieve it?

The simple way, the value is in position (4x - 1):
var list = input.Split(':');
var outputs = new List<string>();
for (int index = 0; index < list.Count(); index++)
{
if (index % 4 == 3)
outputs.Add(list.ElementAt(index));
}

Use String.Split()
http://msdn.microsoft.com/en-us/library/system.string.split.aspx
String myString = "id0:xxxxx:id0-value:xxxxx:id1:xxxxxxxx:id1-value:xxxxx:id3:xxxxxxxx:id3-value:xxx";
String[] tokens = myString.Split(new Char[] {':'});
The token array will contain {"id0","xxxxx","id0-value","xxxxx","id1","xxxxxxxx","id1-value","xxxxx","id3","xxxxxxxx","d3-value","xxx"}
The second possibility is to use String.IndexOf() and String.Substring().
http://msdn.microsoft.com/en-us/library/5xkyx09y
http://msdn.microsoft.com/en-us/library/aka44szs
Int start = 0;
ArrayList tokens;
while((start = myString.IndexOf("-value:", start)) > -1) {
ArrayList.Add(myString.Substring(start+6, myString.IndexOf(":", start+7);
start += 6; // Jump past what we just found.
}

Split it using a Regex(a regex which splits : coming after x), then split using colon : and use first index as a Dictionary Key and Second index as Dictionary value.