I have a list that contains 3 items, two of type_1, and one of type_2. I want to return a second list that contains the type and number of that type that exists. When stepping through the breakpoints set at the foreach loop, the IF statement is never true. I assume there is something wrong with my attempt to use Contains() method.
The output should be something like:
type_1 2
type_2 1
Instead, it evaluates as:
type_1 1
type_1 1
type_2 1
Is my use of Contains() not correct?
public List<item_count> QueryGraphListingsNewAccountReport()
List<item> result = new List<items>();
var type_item1 = new item { account_type = "Type_1" };
var type_item2 = new item { account_type = "Type_1" };
var type_item3 = new item { account_type = "Type_2" };
result.Add(type_item1);
result.Add(type_item2);
result.Add(type_item3);
//Create a empty list that will hold the account_type AND a count of how many of that type exists:
List<item_count> result_count = new List<item_count>();
foreach (var item in result)
{
if (result_count.Contains(new item_count { account_type = item.account_type, count = 1 } ) == true)
{
var result_item = result_count.Find(x => x.account_type == item.account_type);
result_item.count += 1;
result_count.Add(result_item);
}
else
{
var result_item = new item_count { account_type = item.account_type, count = 1 };
result_count.Add(result_item);
}
}
return result_count;
}
public class item
{
public string account_type { get; set; }
}
public class item_count
{
public int count {get; set;}
public string account_type { get; set; }
}
I think your problem is that you don't want to use contains at all. You are creating a new object in your contains statement and, obviously, it isn't contained in your list already because you only just created it. The comparison is comparing references, not values.
Why not just use the find statement that you do in the next line instead? If it returns null, then you know there isn't an item already with that type.
So you could do something like this:
var result_item = result_count.Find(x => x.account_type == item.account_type);
if (result_item != null)
{
result_item.count++;
// note here you don't need to add it back to the list!
}
else
{
// create your new result_item here and add it to your list.
}
Note: Find is o(n), so this might not scale well if you have a really large set of types. In that case, you might be better off with Saeed's suggestion of grouping.
You can do:
myList.GroupBy(x=>x.type).Select(x=>new {x.Key, x.Count()});
If you want use for loop, it's better to use linq Count function to achieve this, If you want use Contains you should implement equal operator as the way you used.
Related
I am trying to get the number of how many times player.userID shows in a list but I can't seem to figure out how, I have searched the internet for an hour now.
class ConfigData
{
[JsonProperty(PropertyName = "Ban")]
public uint ban = 3;
[JsonProperty(PropertyName = "Kick")]
public uint kick = 2;
[JsonProperty(PropertyName = "Banned Message")]
public string kickMessage = "You are banned";
}
class StoredData
{
public List<ulong> Reports = new List<ulong>();
public List<ulong> Banned = new List<ulong>();
public List<ulong> Kicked = new List<ulong>();
}
void OnPlayerConnected(BasePlayer player)
{
int count = storedData.Reports.Count(reportedID => reportedID == player.userID);
Puts($"{player.userID} has {count} reports");
if (count >= configData.ban)
{
storedData.Banned.Add(player.userID);
SaveData();
return;
}
if (storedData.Banned.Contains(player.userID))
{
Network.Net.sv.Kick(player.net.connection, rust.QuoteSafe(configData.kickMessage));
return;
}
else
{
return;
}
}
I can post the full code if needed.
The Count method accepts a lambda that tells it the condition on which to count.
Since your reports are just a list of user IDs, all you need to do is:
int count = storedData.Reports.Count(reportedID => reportedID == player.userID);
if (count >= configData.ban) // NOTE: changed this to >=
{
...
}
As a side note, if it was a list of objects instead, and you wanted to compare to a property named someProperty, then it would be:
report => report.someProperty == player.userID.
A lambda is just a shorthand for a function; the part before the => is the parameter list (here, it just accepts a single parameter - the current element of storedData.Reports). The parameter name is arbitrary (your choice).
The part behind the => is the function body, with implicit return, so
reportedID == player.userID is like
{ return reportedID == player.userID; }.
The Count method basically walks through the IDs in Reports, and for each one, it asks the lambda if it should count it or not, by passing that ID to the lambda, and checking if the lambda returns true or false.
P.S.
In your code it says:
if (!storedData.Banned.Contains(player.userID)) { /* kick */ }
Are you sure you want to kick the players that are not in the banned list? Check the logic that relates to kicking/banning (maybe do some tests), it doesn't look quite right to me.
Recently, I have been getting into C# (ASP.NET) and moving on from PHP. I want to achieve something like this:
mainArray (
array 1 (
'name' => 'example'
),
array 2 (
'name' => 'example2'
)
);
I know that you can use an Array in C# however, you must indicate the length of the Array before doing so which is where the problem is.
I want to loop through a Database in a Class function which returns an Array of all the columns, ie:
id, username, email.
I have tried:
public Array search_bustype(string match, string forthat)
{
db = new rkdb_07022016Entities2();
var tbl = (from c in db.tblbus_business select c).ToArray();
List<string> List = new List<string>();
int i = 0;
foreach (var toCheck in tbl)
{
if (toCheck.BusType.ToString() == match)
{
if (forthat == "Name")
{
List.Add(toCheck.Name);
}
if (forthat == "Address")
{
}
}
i++;
}
return List.ToArray();
}
But as you can see, I am having to only return the single column because the List is not multidimensional (can't be nested).
What can I use to solve this issue? I have looked at some links:
C# Arrays
StackOverflow post
But these again are an issue for my structure since I don't know how many index's I need in the Array when declaring it - The Database grows everyday.
Thanks in advance.
Try something like this. First, define a class for your business model.
public class Person
{
public string Name {get;set;}
public string Address {get;set;}
}
Then use a generic list instead of a string list.
public Person[] search_bustype(string match, string forthat)
{
var db = new rkdb_07022016Entities2();
List<Person> personList = new List<Person>();
foreach (var toCheck in db.tblbus_business.Where(b => b.BusType.ToString() == match))
{
var model = new Person { Name = toCheck.Name, Address = toCheck.Address };
personList.Add(model);
}
return personList.ToArray();
}
I'm not sure what you are trying to do with the forthat variable.
You can use a list of lists
IList<IList<string>> multiList;
This question already has answers here:
Sorting of list contained strings having alphabetic/numeric
(2 answers)
Closed 8 years ago.
I have a class with one property "Name" containing names like "1_[AnnualRevenue]","2_[ResellerType]","3_xxx"....
my class is like
class xxx
{
private string fileName;
public string FileName
{
get { return fileName; }
set { fileName = value; }
}
}
And I am assigning the values to the object of the class. like xxx.FileName="1_[AnnualRevenue]";
Now I have a list class. And now sort the list according to this class property.
Now I want to sort the field according to the numeric order, I mean 1 first 2 second and so on.
And then write it to filestream.
Could any body help me with this.
Thanks in advance.
Since the property is a String but you want to sort it numerically, probably the best way would be to implement IComparable on your class and then put your custom sort code in the CompareTo method. Then you don't have to write a more complex Lambda statement each time you want to Sort a list, you can just call the Sort() method on the list.
You can also handle cases where the FileName property does not contain an underscore or is null, rather than getting exceptions in your OrderBy code (which is what would happen with most of the other answers).
I made a couple of other changes also - override the ToString method so you can easily display the value to the console window, and used Automatic property syntax for the FileName property so we can remove the backing field:
class xxx : IComparable<xxx>
{
public string FileName { get; set; }
public int CompareTo(xxx other)
{
// Short circuit if any object is null, if the
// Filenames equal each other, or they're empty
if (other == null) return 1;
if (FileName == null) return (other.FileName == null) ? 0 : -1;
if (other.FileName == null) return 1;
if (FileName.Equals(other.FileName)) return 0;
if (string.IsNullOrWhiteSpace(FileName))
return (string.IsNullOrWhiteSpace(other.FileName)) ? 0 : -1;
if (string.IsNullOrWhiteSpace(other.FileName)) return 1;
// Next, try to get the numeric portion of the string to compare
int thisIndex;
int otherIndex;
var thisSuccess = int.TryParse(FileName.Split('_')[0], out thisIndex);
var otherSuccess = int.TryParse(other.FileName.Split('_')[0], out otherIndex);
// If we couldn't get the numeric portion of the string, use int.MaxValue
if (!thisSuccess)
{
// If neither has a numeric portion, just use default string comparison
if (!otherSuccess) return FileName.CompareTo(other.FileName);
thisIndex = int.MaxValue;
}
if (!otherSuccess) otherIndex = int.MaxValue;
// Return the comparison of the numeric portion of the two filenames
return thisIndex.CompareTo(otherIndex);
}
public override string ToString()
{
return FileName;
}
}
Now, you can just call Sort on your list:
List<xxx> list = new List<xxx>
{
new xxx {FileName = "13_a"},
new xxx {FileName = "8_a"},
new xxx {FileName = null},
new xxx {FileName = "1_a"},
new xxx {FileName = "zinvalid"},
new xxx {FileName = "2_a"},
new xxx {FileName = ""},
new xxx {FileName = "invalid"}
};
list.Sort();
Console.WriteLine(string.Join("\n", list));
// Output (note the first two are the empty string and the null value):
//
//
// 1_a
// 2_a
// 8_a
// 13_a
// invalid
// zinvalid
You can use LINQ to do that for you
List<xxx> orderedList = unOrderedList.OrderBy(o => Convert.ToInt32(o.FileName.Split('_').First())).ToList();
Editted the answer on behalf of the comments - pointing out that indeed we need to convert to integers to order correctly.
You can do like following to sort the list:
List<xxx> list = new List<xxx>
{
new xxx { FileName = "3_a" },
new xxx { FileName = "1_a" },
new xxx { FileName = "2_a" },
new xxx { FileName = "8_a" }
};
var sorted = list.OrderBy(it => Convert.ToInt32(it.FileName.Split('_')[0]));//using System.Linq;
And you can write the list to disk file as below:
using (TextWriter tw = new StreamWriter("C:\\FileNames.txt"))
{
foreach (var item in sorted)
{
tw.WriteLine(item.FileName.ToString());
}
}
I have a list like
List<VoieData> listVoieData = new List<VoieData>();
and in VoieData Class I have :
public class VoieData
{
public int Depart { set; get; }
public int Arrive { set; get; }
public int DistanceDepart { set; get; }
public int DistanceArrive { set; get; }
}
Since I have a massive values I want to only consider all my Depart number , I would like to filter the listVoieData by finding the Arrive only have the same value as the
Depart
for example I have
listVoieData.Select(p=>p.Depart).ToList()= List<int>{1,2,3};
listVoieData.Select(p=>p.Arrive).ToList()= List<int>{1,2,3,4,5};
I need to throw away the entire VoieData which contain {4,5} as Arrive
right now my soulution is like this , but it' s not correct ;
List<VoieData> listVoieDataFilter = listVoieData .Join(listVoieData , o1 => o1.Arrive, o2 => o2.Depart, (o1, o2) => o1).ToList();
Sorry for the confusing question ;
I want to remove Arrive which is different from all the Depart in the list list , and return the new
List
it 's not only in one VoieData;
Arrive!=Depart
Thanks
I think you want to remove all objects where Arrive is not in any of the Depart from any object. In that case, first get all Depart and then filter by Arrive:
HashSet<int> allDepart = new HashSet<int>(listVoieData.Select(x => x.Depart));
var result = listVoieData.Where(v => !allDepart.Contains(v.Arrive))
We use a HashSet<int> for efficiency.
Use LINQ Where:
var records = listVoieData.Where(x => x.Arrive == x.Depart);
This will return results where both Arrive and Depart are the same.
That would be a typical case to use linq.
something like:
var res = from data in listVoieData
where data.Depart == data.Arrive
select data;
and then optionally just use res.ToArray() to run the query and get the array.
Since you've stated that you want:
I want to remove Arrive which is different from all the Depart
This can be re-phrased as, "The set of all arrivals except those in the set of departures", which translates very nicely into the following LINQ query:
var arrivalsWithNoDepartures = listVoieData.Select(p=>p.Arrive)
.Except(listVoieData.Select(p=>p.Depart));
I really have no clue about enumerated list, but after some research I found that this list may help solve my problem. So I have a string in my settings called strGrades, and it is a range of strings that I manually update. The range is 0155-0160, 0271-0388, 0455-0503, 0588-687. What I basically want to do is find the values that are not in this grade list (for example 0161,0389, 0504-0587...)
So I came up with a function that will allow me to get each match in the grade range:
public static List<GradeRange> GetValidGrades()
{
MatchCollection matches= Regex.Matches(Settings.Default.productRange,
Settings.Default.srGradeRange);
List<GradeRange> ranges= new List<GradeRange();
if(matches.Count >0)
{
foreach (Match match in matches)
{
ranges.Add(new GradeRange() 23 {
Start= int.Parse(match.Groups["Start"].Value),
Stop= int.Parse(match.Groups["Stop"].Value)
});
}
}
return ranges;
}
here is the grade range class
public class GrandRange
{
public int Start{get; set;)
public int Stop {get; set; )
}
So the function above caputures my Start and End values, can anyone please help me get this into a list where I can find the values that fall outside of the range values, I just need a starting point. Thanks so much!
You could use a custom extension method that creates .Between along with a Where
var myFilteredList = list.Where(x=>!myValue.Between(x.Start, x.Stop, true));
This isnt the most performant answer, but if you need a list of all the numbers that are not between certain ranges, then you could do something like this:
var missingNumbers = new List<int>();
var minStop = list.OrderBy(x=>x.Stop).Min().Stop;
var maxStart = list.OrderBy(x=>x.Start).Max().Start;
Enumerable.Range(minStop, maxStart).ToList()
.ForEach(x=>
{
if(!x.Between(x.Start, x.Stop, true))
missingNumbers.Add(x);
}
);
Here this should get you started
var strings = "0155-0160, 0271-0388, 0455-0503, 0588-687";
var splitStrings = strings.Split(char.Parse(","));
var grads = new List<GrandRange>();
foreach (var item in splitStrings) {
var splitAgain = item.Split(char.Parse("-"));
var grand = new GrandRange
{
Start = int.Parse(splitAgain[0]),
Stop = int.Parse(splitAgain[1])
};
grads.Add(grand);
}
}