Develop Reference

Filter data from list of JSON string

I have a list of json string like this
{}
{"RuleId":"20cf47c5-3674-4a39-8553-00348f860fe7"}
{}
{"RuleId":"3047c5-3674-4a39-7753-003477860fe7"}
{}
{"RuleId":"20cf47c5-3674-4a39-8553-00348f860fe7"}
{"RuleId":"55cf47c5-3674-4a39-8553-00366f860hh7"}
now I want to get the count of element that match a rule id. How to do that with linq

Do the following:
string pattern = #"<a regular expression pattern>";
Regex rgx = new Regex(pattern, RegexOptions.IgnoreCase);
var num = jsonList.Count(x => rgx.Matches(JObject.Parse(x)["RuleId"]).Count > 0);
Or in a simple case:
string specifiedId = "<Id>";
var num = jsonList.Count(x => JObject.Parse(x)["RuleId"] == specifiedId);

This is what I understand from your question: count a given id in elements of a list.
var ruleId = "20cf47c5-3674-4a39-8553-00348f860fe7";
var list = new List<KeyValuePair<string, string>>
{
new KeyValuePair<string, string>("RuleId", "20cf47c5-3674-4a39-8553-00348f860fe7"),
new KeyValuePair<string, string>("RuleId", "3047c5-3674-4a39-7753-003477860fe7"),
new KeyValuePair<string, string>("RuleId", "20cf47c5-3674-4a39-8553-00348f860fe7"),
new KeyValuePair<string, string>("RuleId", "55cf47c5-3674-4a39-8553-00366f860hh7")
};
var count = list.Count(x => x.Value == ruleId);

String data to be converted to Dictionary

I have a String
string data = "[City, Delhi]&[State, DL]&[Country, IN]";
from which I want a dictionary.
The approach I thought was
Split on "&"
In the resulting Array, parse each element
2.1 Replace "[" and "]"
2.2 Insert into the Dictionary
I hate this approach because my string already has "[" and "]" and I should be able to add it directly to Dictionary.

This is a good use case for regular expressions.
var d = Regex.Matches(data, #"\[(?<k>[^,]+), (?<v>[^]]+)\]")
.OfType<Match>()
.ToDictionary(m => m.Groups["k"].Value, m => m.Groups["v"].Value);

The approach you describe is probably as good as it's going to get.
A naive implementation (without error handling) would be:
var pairs = data.Split('&');
var dict = new Dictionary<string, string>();
foreach (var pair in pairs)
{
var parts = pair.Split(',');
dict.Add(
parts[0].TrimStart('['),
parts[1].TrimStart().TrimEnd(']'));
}
Or, using a regular expression to obtain the keys and values:
string data = "[City, Delhi]&[State, DL]&[Country, IN]";
var pairs = data.Split('&');
var dict = new Dictionary<string, string>();
var regex = new System.Text.RegularExpressions.Regex(#"\[(?<key>.*), (?<value>.*)\]");
foreach (var pair in pairs)
{
var match = regex.Match(pair);
// TODO: Error if match.Success == false ?
dict.Add(match.Groups["key"].Value, match.Groups["value"].Value);
}

You can try this using linq
string data = "[City, Delhi]&[State, DL]&[Country, IN]";
string[] arr = data.Replace("[", "").Replace("]", "").Split('&');
var dict = arr.ToList().ToDictionary(x => x.Split(',')[0], x => x.Split(',')[1]);

Try this...
private static void Splitter()
{
string data = "[City, Delhi]&[State, DL]&[Country, IN]";
Dictionary<string,string> dOutput = new Dictionary<string,string>();
string[] sArr = data.Split('&');
var v = from p in sArr
select p.Replace("[", "").Replace("]", "").Split(',');
var v2 = (from p in v
select p).ToDictionary(item => item[0], item => item[1]);
Console.WriteLine(v2.Count());
}
v2 is a dictionary object...

How to Sort NameValue Collection and Store it in a string

Here I am storing two set of querystring parameters into two different namevalue collection. The querystring parameter order may vary so I just want to sort the order and then I need to store namevalue collection to a string.
Updated Code :
string url1 = #"http://www.somewebsitesampletest.com/dcs7o?data=142248494&dcp=smre&nparam=4567P&email=xxx.com";
string url2 = #"http://www.somewebsitesampletest.com/dcs7o?dcp=smre&data=142248494&email=xxx.com&nparam=4567P";
var NameValueCollection1 = HttpUtility.ParseQueryString(url1);
var NameValueCollection2 = HttpUtility.ParseQueryString(url2);
ExpectedResult:
After Sorting and converting to string the result should look like the below one
string query1 = "data=142248494&dcp=smre&email=xxx.com&nparam=4567P";
string query2 = "data=142248494&dcp=smre&email=xxx.com&nparam=4567P";

Here's a solution using Linq.
Basically it changes the NameValueCollection to an IEnumerable of the keys using Cast<T>, then the rest is fairly self explanatory.
public string GetSortedQueryString(string url)
{
var queryString = HttpUtility.ParseQueryString(url);
// Ignore null keys (caused by your ?& at the start of the query string
var orderedKeys = queryString.Cast<string>().Where(k => k != null).OrderBy(k => k);
return string.Join("&", orderedKeys.Select(k => string.Format("{0}={1}", k, queryString[k])));
}
Results for your URLs would be:
data=142248494&dcp=smre&email=xxx.com&nparam=4567P
data=142248494&dcp=smre&email=xxx.com&nparam=4567P
Email comes before nparam, unlike your expected solution (I'm assuming that was a mistake).

use LINQ with a Dictionary and a list of KeyValuePair :
string url1 = #"http://www.somewebsitesampletest.com/dcs7o?&data=142248494&dcp=smre&nparam=4567P&email=xxx.com";
string query1 ="";
Dictionary<String, String> paramDict = new Dictionary<string, string>();
var query = from match in urlString.Split('?').Where(m => m.Contains('='))
.SelectMany(pr => pr.Split('&'))
where match.Contains('=')
select new KeyValuePair<string, String>(
match.Split('=')[0],
match.Split('=')[1]);
query.ToList().ForEach(kvp => paramDict.Add(kvp.Key, kvp.Value));
var List<KeyValuePair<string, string>> paramList = paramDict.ToList();
paramList.Sort();
foreach (KeyValuePair<string, int> pair in list)
{
query1+=pair.Key+"="+pair.Value+"&";
}
query1=query1.TrimEnd('&');

I made this fiddle because I needed to sort querystring values in order to properly compare URIs: (H/T to Jacob's answer)
https://dotnetfiddle.net/eEhkNk
This preserves duplicate keys:
public static string[] QueryStringOmissions = new string[] { "b" };
public static NameValueCollection SortAndRemove(NameValueCollection collection)
{
var orderedKeys = collection.Cast<string>().Where(k => k != null).OrderBy(k => k);
var newCollection = HttpUtility.ParseQueryString(String.Empty);
foreach(var key in orderedKeys)
{
if (!QueryStringOmissions.Contains(key))
{
foreach(var val in collection.GetValues(key).Select(x => x).OrderBy(x => x).ToArray())
{
newCollection.Add(key, val);
}
}
}
return newCollection;
}

Need to create a Dictionary <int, List<string>> using c#

I have following file names in my files folder
1000_A.csv
1000_B.csv
1000_C.csv
1001_A.csv
1001_B.csv
files names starting with same ID needs to be added to a list and then the list needs to added to a dictionary with ID as key
For ex:
list x contains "1000_A.csv", "1000_B.csv", "1000_C.csv"
add this to a dictionary with ID 1000 as the key Please help.

You can use LINQ's GroupBy:
Dictionary<int, List<string>> idFilenames = fileList
.Select(fileName =>
{
string fnwoe = Path.GetFileNameWithoutExtension(fileName);
string idPart = fnwoe.Split('_').First();
int id;
int.TryParse(idPart, out id);
return new { fileName, id };
})
.GroupBy(x => x.id)
.ToDictionary(g => g.Key, g => g.Select(x => x.fileName).ToList());

var folder = GetFolder();
var files = new Dictionary<int, List<string>>();
foreach (var file in folders)
{
int id = Convert.ToInt32(file.Substring(0, file.IndexOf('_'));
if (files.Any(x => x.Key == id))
files[id].Add(file);
else
{
var newList = new List<string>();
newList.Add(file);
files.Add(id, newList);
}
}

var listOfFiles = ...; // assuming you can read the list of filenames
// into a string[] or IList<string>
var d = listOfFiles.GroupBy( f => f.Substring( 0, f.IndexOf( '_' ) ) )
.ToDictionary( g => g.Key, g => g );

e.g CSV the list of your csv files
Loop through you CSV list:
Dictionary<string, int> Dict = new Dictionary<string, int>();
List<string> files = new List<string>();
foreach (string path CSV)
{
if(!ContainsKey(path.Substring(0,3))
{
files.Add(path);
Dict.Add(path.Substring(0,3),files);
}
else
{
files.Add(path);
Dict[path.Substring(0,3)].Add(file);
}
}

splitting string in dictionary

How do I split the following string
string s = "username=bill&password=mypassword";
Dictionary<string,string> stringd = SplitTheString(s);
such that I could capture it as follows:
string username = stringd.First().Key;
string password = stringd.First().Values;
Please let me know. Thanks

You can populate the dictionary list like so:
Dictionary<string, string> dictionary = new Dictionary<string, string>();
string s = "username=bill&password=mypassword";
foreach (string x in s.Split('&'))
{
string[] values = x.Split('=');
dictionary.Add(values[0], values[1]);
}
this would allow you to access them like so:
string username = dictionary["username"];
string password = dictionary["password"];
NOTE: keep in mind there is no validation in this function, it assumes your input string is correctly formatted

It looks like you are trying to parse a query string - this is already built in, you can use HttpUtility.ParseQueryString() for this:
string input = "username=bill&password=mypassword";
var col = HttpUtility.ParseQueryString(input);
string username = col["username"];
string password = col["password"];

I think something similar to this should work
public Dictionary<string, string> SplitTheStrings(s) {
var d = new Dictionary<string, string>();
var a = s.Split('&');
foreach(string x in a) {
var b = x.Split('=');
d.Add(b[0], b[1]);
}
return d;
}

var splitString = "username=bill&password=pass";
var splits = new char[2];
splits[0] = '=';
splits[1] = '&';
var items = splitString.Split(splits);
var list = new Dictionary<string, string> {{items[1], items[3]}};
var username = list.First().Key;
var password = list.First().Value;
this my also work

If Keys will not repeat
var dict = s.Split('&').Select( i=>
{
var t = i.Split('=');
return new {Key=t[0], Value=t[1]};}
).ToDictionary(i=>i.Key, i=>i.Value);
If Keys can repeat
string s = "username=bill&password=mypassword";
var dict = s.Split('&').Select( i=>
{
var t = i.Split('=');
return new {Key=t[0], Value=t[1]};}
).ToLookup(i=>i.Key, i=>i.Value);

The other answers are better, easier to read, simpler, less prone to bugs, etc, but an alternate solution is to use a regular expression like this to extract all the keys and values:
MatchCollection mc = Regex.Matches("username=bill&password=mypassword&","(.*?)=(.*?)&");
Each match in the match collection will have two groups, a group for the key text and a group for the value text.
I am not too good at regular expressions so I don't know how to get it to match without adding the trailing '&' to the input string...