I have a list of paths that look like
//servername/d$/directory
I am getting the serverName from the path with the following
var host = somePath.Split(new[] { '\\' }, StringSplitOptions.RemoveEmptyEntries).FirstOrDefault();
I want to refine this list to only 1 server Name listed (say the first one found)
Example
if the list contains
//serverA/d$/directoryA
//serverA/d$/directoryB
//serverA/d$/directoryC
//serverB/d$/directoryD
//serverB/d$/directoryE
the list would turn into
//serverA/d$/directoryA
//serverB/d$/directoryD
You can group them by the server name (by trimming the start and splitting on the / character and taking the first item), and then select the first item from each group into a new list:
var serverNames = new List<string>
{
"//serverA/d$/directoryA",
"//serverA/d$/directoryB",
"//serverA/d$/directoryC",
"//serverB/d$/directoryD",
"//serverB/d$/directoryE",
};
var results = serverNames
.GroupBy(name => name.TrimStart('/').Split('/')[0])
.Select(group => group.First())
.ToList();
From your first code example it's not clear if the paths begin with \, so to handle both cases you can do:
var results = serverNames
.GroupBy(name => name.TrimStart('\\', '/', ' ').Split('\\', '/')[0])
.Select(group => group.First())
.ToList();
Related
I am working on project which is asp.net mvc core. I want to replace string list of duplicate values to one with comma separated,
List<string> stringList = surveylist.Split('&').ToList();
I have string list
This generate following output:
7=55
6=33
5=MCC
4=GHI
3=ABC
1003=DEF
1003=ABC
1=JKL
And I want to change output like this
7=55
6=33
5=MCC
4=GHI
3=ABC
1003=DEF,ABC
1=JKL
Duplicate items values should be comma separated.
There are probably 20 ways to do this. One simple one would be:
List<string> newStringList = stringList
.Select(a => new { KeyValue = a.Split("=") })
.GroupBy(a => a.KeyValue[0])
.Select(a => $"{a.Select(x => x.KeyValue[0]).First()}={string.Join(",", a.Select(x => x.KeyValue[1]))}")
.ToList();
Take a look at your output. Notice that an equal sign separates each string into a key-value pair. Think about how you want to approach this problem. Is a list of strings really the structure you want to build on? You could take a different approach and use a list of KeyValuePairs or a Dictionary instead.
If you really need to do it with a List, then look at the methods LINQ's Enumerable has to offer. Namely Select and GroupBy.
You can use Select to split once more on the equal sign: .Select(s => s.Split('=')).
You can use GroupBy to group values by a key: .GroupBy(pair => pair[0]).
To join it back to a string, you can use a Select again.
An end result could look something like this:
List<string> stringList = values.Split('&')
.Select(s => {
string[] pair = s.Split('=');
return new { Key = pair[0], Value = pair[1] };
})
.GroupBy(pair => pair.Key)
.Select(g => string.Concat(
g.Key,
'=',
string.Join(
", ",
g.Select(pair => pair.Value)
)
))
.ToList();
The group contains pairs so you need to select the value of each pair and join them into a string.
I have a predefined list List words.Say it has 7 elements:
List<string> resourceList={"xyz","dfgabr","asxy", "abec","def","geh","mnbj"}
Say, the user gives an input "xy+ ab" i.e he wants to search for "xy" or "ab"
string searchword="xy+ ab";
Then I have to find all the words in the predefined list which have "xy" or "ab" i.e all words split by '+'
So, the output will have:
{"xyz","dfgabr","abec",""}
I am trying something like:
resourceList.Where(s => s.Name.ToLower().Contains(searchWords.Any().ToString().ToLower())).ToList()
But, I am unable to frame the LINQ query as there are 2 arrays and one approach I saw was concatenate 2 arrays and then try; but since my second array only contains part of the first array, my LINQ does not work.
You need to first split your search pattern with + sign and then you can easily find out which are those item in list that contains your search pattern,
var result = resourceList.Where(x => searchword.Split('+').Any(y => x.Contains(y.Trim()))).ToList();
Where:
Your resourceList is
List<string> resourceList = new List<string> { "xyz", "dfgabr", "asxy", "abec", "def", "geh", "mnbj" };
And search pattern is,
string searchword = "xy+ ab";
Output: (From Debugger)
Try following which doesn't need Regex :
List<string> resourceList= new List<string>() {"xyz","dfgabr","asxy","abec","def","geh","mnbj"};
List<string> searchPattern = new List<string>() {"xy","ab"};
List<string> results = resourceList.Where(r => searchPattern.Any(s => r.Contains(s))).ToList();
You can try querying with a help of Linq:
List<string> resourceList = new List<string> {
"xyz", "dfgabr", "asxy", "abec", "def", "geh", "mnbj"
};
string input = "xy+ ab";
string[] toFind = input
.Split('+')
.Select(item => item.Trim()) // we are looking for "ab", not for " ab"
.ToArray();
// {"xyz", "dfgabr", "asxy", "abec"}
string[] result = resourceList
.Where(item => toFind
.Any(find => item.IndexOf(find) >= 0))
.ToArray();
// Let's have a look at the array
Console.Write(string.Join(", ", result));
Outcome:
xyz, dfgabr, asxy, abec
If you want to ignore case, add StringComparison.OrdinalIgnoreCase parameter to IndexOf
string[] result = resourceList
.Where(item => toFind
.Any(find => item.IndexOf(find, StringComparison.OrdinalIgnoreCase) >= 0))
.ToArray();
I have some code that takes a string and processes it by splitting it into words, and giving the count of each word.
The trouble is it only returns void, because I am only able to print to the screen after the processing is done. Is there any way I can save the results in an arraylist, so that that I can return it to the method that called it?
The current code:
message.Split(' ').Where(messagestr => !string.IsNullOrEmpty(messagestr))
.GroupBy(messagestr => messagestr).OrderByDescending(groupCount => groupCount.Count())
.Take(20).ToList().ForEach(groupCount => Console.WriteLine("{0}\t{1}", groupCount.Key, groupCount.Count()));
Thank you.
Try this code
var wordCountList = message.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
.GroupBy(messagestr => messagestr)
.OrderByDescending(grp => grp.Count())
.Take(20) //or take the whole
.Select(grp => new KeyValuePair<string, int>(grp.Key, grp.Count()))
.ToList(); //return wordCountList
//usage
wordCountList.ForEach(item => Console.WriteLine("{0}\t{1}", item.Key, item.Value));
If you want, you can return the wordCountList which is a List<KeyValuePair<string, int>> containing all the words and their counts in descending order.
How you can use that, is also shown in the last line.
And rather than taking first 20 from the list, if you want to take the whole, remove this .Take(20) part.
First of all, by calling Take(20) you just take the first 20 words and put the others away. So, if you want all the results, remove it.
After that, you can do it like this:
var words = message.Split(' ').
Where(messagestr => !string.IsNullOrEmpty(messagestr)).
GroupBy(messagestr => messagestr).
OrderByDescending(groupCount => groupCount.Count()).
ToList();
words.ForEach(groupCount => Console.WriteLine("{0}\t{1}", groupCount.Key, groupCount.Count()));
To put the results into some other data structure, you can use one of these ways:
var w = words.SelectMany(x => x.Distinct()).ToList(); //Add this line to get all the words in an array
// OR Use Dictionary
var dic = new Dictionary<string, int>();
foreach(var item in words)
{
dic.Add(item.Key, item.Count());
}
I suppose that this question might partially duplicate other similar questions, but i'm having troubles with such a situation:
I want to extract from some string sentences
For example from
`string sentence = "We can store these chars in separate variables. We can also test against other string characters.";`
I want to build an IEnumerable words;
var separators = new[] {',', ' ', '.'};
IEnumerable<string> words = sentence.Split(separators, StringSplitOptions.RemoveEmptyEntries);
After that, go throught all these words and take firs character into a distinct ascending ordered collection of characters.
var firstChars = words.Select(x => x.ToCharArray().First()).OrderBy(x => x).Distinct();
After that, go through both collections and for each character in firstChars get all items from words which has the first character equal with current character and create a Dictionary<char, IEnumerable<string>> dictionary.
I'm doing this way:
var dictionary = (from k in firstChars
from v in words
where v.ToCharArray().First().Equals(k)
select new { k, v })
.ToDictionary(x => x);
and here is the problem: An item with the same key has already been added.
Whis is because into that dictionary It is going to add an existing character.
I included a GroupBy extension into my query
var dictionary = (from k in firstChars
from v in words
where v.ToCharArray().First().Equals(k)
select new { k, v })
.GroupBy(x => x)
.ToDictionary(x => x);
The solution above gives makes all OK, but it gives me other type than I need.
What I should do to get as result an Dictionary<char, IEnumerable<string>>dictionary but not Dictionary<IGouping<'a,'a>> ?
The result which I want is as in the bellow image:
But here I have to iterate with 2 foreach(s) which will Show me wat i want... I cannot understand well how this happens ...
Any suggestion and advice will be welcome. Thank you.
As the relation is one to many, you can use a lookup instead of a dictionary:
var lookup = words.ToLookup(word => word[0]);
loopkup['s'] -> store, separate... as an IEnumerable<string>
And if you want to display the key/values sorted by first char:
for (var sortedEntry in lookup.OrderBy(entry => entry.Key))
{
Console.WriteLine(string.Format("First letter: {0}", sortedEntry.Key);
foreach (string word in sortedEntry)
{
Console.WriteLine(word);
}
}
You can do this:
var words = ...
var dictionary = words.GroupBy(w => w[0])
.ToDictionary(g => g.Key, g => g.AsEnumerable());
But for matter, why not use an ILookup?
var lookup = words.ToLookup(w => w[0]);
I have a string comma separated list of some data. I have another list of strings of keywords that i want to search for in the first list. I want to have returned to me the index of all the elements in the first list that do no contain any of the keywords in the second list. For example:
List 1:
Student,101256,Active
Professor,597856,Active
Professor,697843,Inactive
Student,329741,Active
Student,135679,Inactive
Student,241786,Inactive
List 2:
697843
241786
My query on List 1 should be, give me all the index of all the elements that do not contain any of the elements of list 2. Therefore, the return list of indices should be 0,1,3,4. Is there any way to accomplish this?
Thanks in advance!
Edit: This is my try:
List<int> index = list1
.Select((s, i) => new { s, i })
.Where(e => !list2.Contains(e.s))
.Select(e => e.i).ToList();
You will need to reference System.Linq, this has now been edited to include the !Student filter
var list1 = new List<string> {
{"Student,101256,Active"},
{"Professor,597856,Active"},
{"Professor,697843,Inactive"},
{"Student,329741,Active"},
{"Student,135679,Inactive"},
{"Student,241786,Inactive"}
};
var list2 = new List<string> {{"697843"}, {"241786"}};
var result = list1
.Select((item,i)=> new {index=i,value=item})
.Where(item => !item.value.StartsWith("Student"))
.Where(item => !item.value.Split(',').Any(j => list2.Contains(j)))
.Select(item=>item.index)
.ToList();
The first select extracts the index before filtering, the pre-edited version calculated the index after the filter and so was incorrect.