CODEWITHSUNDEEP
c#listobject
Choy
Choy

Reputation: 482

how to count the occurrence of the property in list of object

I have 2 list of objects

   List<Student> studentList = new List<Student>() { 


      new Student(){ StudentName="Bill", MobileOS = "Android"},
      new Student(){ StudentName="Bill", MobileOS = "Android"}
      new Student(){ StudentName="Steve",MobileOS = "IOS"},
      new Student(){ StudentName="Ram",  MobileOS = "IOS"},
      new Student(){ StudentName="Bill", MobileOS = "IOS"}
}

In my other list, I want to store filtered data. Example

    List<FilteredData> filteredData= new List<FilteredData>(){

          new FilteredData(){ StudentName="Bill", Count=3, Android = 2, Ios = 1},
          new FilteredData(){ StudentName="Steve",Count=1, Android = 0, Ios = 1},
          new FilteredData(){ StudentName="Ram",  Count=1, Android = 0, Ios = 1},
}

Noted: the Count value is based on the occurrence of same StudentName and the number of Android and Ios is based on MobileOS

So, how can I count the same Student name and store it into a new list? I searched whole day but seems can't found a solution for this

Upvotes: 0

Views: 117

Answers (2)

Martin Staufcik
Martin Staufcik

Reputation: 9482

var filtereddata = studentList
    .GroupBy(x => x.SudentID)
    .Select(x => new FilteredData() { 
         StudentID = x.Key, 
         StudentName = x.First().StudentName, 
         Count = x.Count(),
         Android = x.Count(y => y.MobileOS == "Android"),
         Ios = x.Count(y => y.MobileOS == "IOS")
    });

Upvotes: 1

Jannik Botteram
Jannik Botteram

Reputation: 46

Using linq you could reduce it to

var filteredData =
    studentList
        .GroupBy(item => item.StudentName)
        .Select(group => new FilteredData 
        {
            StudentID = group.First().StudentID, 
            StudentName = group.Key, 
            Count = group.Count() 
        })
        .ToList();

Upvotes: 2

Related Questions