Android Code Snippet Student Position Ranking

Hello everyone and Happy Holidays
So I was searching the community for a snippet for student ranking for a system I was building last month but never came accross a what I needed. I found a JavaScript on stackoverflow and re-wrote it in b4x
So I'm sharing for future/existing members who may need it.

function calculatePosition(data){
    var json = data;
    json.sort((a, b) => b.total - a.total);
    for (let i = 0; i < json.length; i++) {
        let totalPoints = json[i].total;
        let studentsWithRank = json.filter(student => student.total === totalPoints);
        for (let student of studentsWithRank) {
            student.rank = i + 1;
        }
        i += studentsWithRank.length - 1;
    }
    console.log(json);
    return json;
}

The B4X Code Below

The Type can be changed to anything as long as there is something to enable ranking (ie. TotalScore, Rank)

Type StudentScore(Total As Int, Year As String, StudentID As String, Term As Int, Class As String, Rank As Int)

Filters the List to find similar scores and returns a list(rList).
Filter - is the item to be filtered out in the List

Public Sub FilterList(List As List, Filter As Object) As List
    Dim rList As List : rList.Initialize
    For i = 0 To List.Size-1
        Dim score As StudentScore = List.Get(i)
        If score.Total == Filter Then
            rList.Add(score)
        End If
    Next
    Return rList
End Sub

This performs the overall calculations returning a List with the Ranks assigned

Public Sub CalculatePosition(List As List) As List
    Dim posList As List : posList.Initialize
    For i = 0 To List.Size-1
        Dim score As StudentScore = List.Get(i)
        Dim totalPoints As Int = score.Total
        Dim studentsWithRank As List = FilterList(List,totalPoints)
        For Each student As StudentScore In studentsWithRank
            student.Rank = i + 1
            Log(student.Rank)
            posList.Add(student)
        Next
        i = i + studentsWithRank.Size-1
    Next
    Return posList
End Sub

Similar to CalculatePosition but only gets one Students position

Public Sub GetPosition(List As List, StudentID As String) As Int
    Dim Position As Int
    Dim posList As List : posList.Initialize
    For i = 0 To List.Size-1
        Dim score As StudentScore = List.Get(i)
        Dim totalPoints As Int = score.Total
        Dim studentsWithRank As List = FilterList(List,totalPoints)
        For Each student As StudentScore In studentsWithRank
            student.Rank = i + 1
            posList.Add(student)
        Next
        i = i + studentsWithRank.Size-1
    Next
    For i = 0 To posList.Size-1
        Dim score As StudentScore = posList.Get(i)
        If score.StudentID == StudentID Then
            Position = score.Rank
        End If
    Next
    Return Position
End Sub

Attached the number suffix(ie 1st, 2nd, 3rd)

public Sub OrdinalSuffixOf(i As Int) As String
    If i == 0 Then
        Return i
    Else
        Dim j As Int = i Mod 10
        Dim k As Int = i Mod 100
        If (j == 1 And k <> 11) Then
            Return i & "st"
        End If
        If (j == 1 And k <> 11) Then
            Return i & "st"
        End If
        If (j == 2 And k <> 12) Then
            Return i & "nd"
        End If
        If (j == 3 And k <> 13) Then
            Return i & "rd"
        End If
        Return i & "th"
    End If
End Sub

Data to be based can be JSON, an Array or List with objects

    Dim List As List : List.initialize
    Dim DataString As String = $"[{"total":603,"yeargroup":"2022\/2023","student_id":70,"term":3,"class":"KG 1"},{"total":603,"yeargroup":"2022\/2023","student_id":74,"term":3,"class":"KG 1"},{"total":603,"yeargroup":"2022\/2023","student_id":124,"term":3,"class":"KG 1"},{"total":168,"yeargroup":"2022\/2023","student_id":82,"term":3,"class":"KG 1"},{"total":166,"yeargroup":"2022\/2023","student_id":72,"term":3,"class":"KG 1"},{"total":163,"yeargroup":"2022\/2023","student_id":81,"term":3,"class":"KG 1"},{"total":153,"yeargroup":"2022\/2023","student_id":472,"term":3,"class":"KG 1"},{"total":153,"yeargroup":"2022\/2023","student_id":84,"term":3,"class":"KG 1"},{"total":150,"yeargroup":"2022\/2023","student_id":77,"term":3,"class":"KG 1"},{"total":148,"yeargroup":"2022\/2023","student_id":79,"term":3,"class":"KG 1"},{"total":142,"yeargroup":"2022\/2023","student_id":76,"term":3,"class":"KG 1"},{"total":138,"yeargroup":"2022\/2023","student_id":73,"term":3,"class":"KG 1"},{"total":136,"yeargroup":"2022\/2023","student_id":471,"term":3,"class":"KG 1"},{"total":135,"yeargroup":"2022\/2023","student_id":75,"term":3,"class":"KG 1"},{"total":131,"yeargroup":"2022\/2023","student_id":83,"term":3,"class":"KG 1"},{"total":125,"yeargroup":"2022\/2023","student_id":80,"term":3,"class":"KG 1"},{"total":121,"yeargroup":"2022\/2023","student_id":473,"term":3,"class":"KG 1"},{"total":102,"yeargroup":"2022\/2023","student_id":71,"term":3,"class":"KG 1"},{"total":98,"yeargroup":"2022\/2023","student_id":470,"term":3,"class":"KG 1"}]"$
    Dim DataList As List
    Dim Parser As JSONParser
    Parser.Initialize(DataString)
    DataList = Parser.NextArray
    For s = 0 To DataList.Size-1
        Dim m As Map = DataList.Get(s)
        Dim score As StudentScore
        score.Initialize
        score.Total = m.Get("total")
        score.Year = m.Get("yeargroup")
        score.StudentID = m.Get("student_id")
        score.Term = m.Get("term")
        score.class = m.Get("class")
        List.Add(score)
        Log(OrdinalSuffixOf(GetPosition(List,score.StudentID)))
    Next

 

[Claude Obiri Amadu]

Sample Output