read write csv file vba code example

Example 1: excel vba open text file

'VBA function to open text file and retrieve the entire content
'as a string:

Function OpenTextFile$(f)
    With CreateObject("ADODB.Stream")
        .Charset = "utf-8"
        .Open
        .LoadFromFile f
        OpenTextFile = .ReadText
    End With
End Function

'--------------------------------------------------------------------

s = OpenTextFile("C:\123.json")
MsgBox Len(s)

Example 2: vba load csv

'VBA function to open a CSV file in memory and parse it to a 2D
'array without ever touching a worksheet:

Function ArrayFromCSV(sFile$)
    Dim c&, i&, j&, p&, d$, s$, rows&, cols&, a, r, v
    Const Q = """", QQ = Q & Q
    Const ENQ = ""  'Chr(5)
    Const ESC = ""  'Chr(27)
    Const COM = ","
    
    d = OpenTextFile$(sFile)
    If LenB(d) Then
        r = Split(Trim(d), vbCrLf)
        rows = UBound(r) + 1
        cols = UBound(Split(r(0), ",")) + 1
        ReDim v(1 To rows, 1 To cols)
        For i = 1 To rows
            s = r(i - 1)
            If LenB(s) Then
                If InStrB(s, QQ) Then s = Replace(s, QQ, ENQ)
                For p = 1 To Len(s)
                    Select Case Mid(s, p, 1)
                        Case Q:   c = c + 1
                        Case COM: If c Mod 2 Then Mid(s, p, 1) = ESC
                    End Select
                Next
                If InStrB(s, Q) Then s = Replace(s, Q, "")
                a = Split(s, COM)
                For j = 1 To cols
                    s = a(j - 1)
                    If InStrB(s, ESC) Then s = Replace(s, ESC, COM)
                    If InStrB(s, ENQ) Then s = Replace(s, ENQ, Q)
                    v(i, j) = s
                Next
            End If
        Next
        ArrayFromCSV = v
    End If
End Function


Function OpenTextFile$(f)
    With CreateObject("ADODB.Stream")
        .Charset = "utf-8"
        .Open
        .LoadFromFile f
        OpenTextFile = .ReadText
        .Close
    End With
End Function