在數據處理方面，Excel是很方便的工具，然而在前端開發中，我們常常需要將Excel文件轉換成JSON數據格式來展示在頁面上。這個轉換過程可以通過一些工具來實現，比如在線工具json-csv.com或者使用VBA宏編寫代碼來完成轉換。今天我們將介紹使用VBA宏編寫實現Excel轉換成JSON格式的過程。

Sub ConvertToJSON()
Dim arr() As String
Dim obj As Object
Dim i As Integer, j As Integer, k As Integer
Dim col As Integer, row As Integer
Dim header As String
'獲取當前工作表中的數據范圍
col = ActiveSheet.UsedRange.Columns.Count
row = ActiveSheet.UsedRange.Rows.Count
'遍歷每一行，把數據保存到一維數組arr中
ReDim arr(row - 2) As String
k = 0
For i = 2 To row
header = ""
For j = 1 To col
If j = 1 Then
header = Cells(1, j).Value
Else
header = header & "|" & Cells(1, j).Value
End If
arr(k) = arr(k) & ",""" & Cells(i, j).Value & """"
Next j
k = k + 1
Next i
'創建字典對象并以header為key，將數據添加到字典中
Set obj = CreateObject("Scripting.Dictionary")
For i = 0 To UBound(arr)
If Not obj.Exists(Split(header, "|")(0) & "_" & Split(header, "|")(1)) Then
obj.Add Split(header, "|")(0) & "_" & Split(header, "|")(1), "[]"
End If
obj(Split(header, "|")(0) & "_" & Split(header, "|")(1)) = obj(Split(header, "|")(0) & "_" & Split(header, "|")(1)) & IIf(obj(Split(header, "|")(0) & "_" & Split(header, "|")(1)) = "[]", "[", ",")
obj(Split(header, "|")(0) & "_" & Split(header, "|")(1)) = obj(Split(header, "|")(0) & "_" & Split(header, "|")(1)) & "{" & Mid(arr(i), 2) & "}"
Next i
'將字典對象轉換成JSON格式的字符串并輸出
Debug.Print "{"
For Each key In obj
Debug.Print """" & key & """:" & Replace(obj(key), "[,", "[") & "],"
Next key
Debug.Print "}"
End Sub

上述代碼可將Excel中的數據轉化成嵌套的JSON格式。具體實現過程如下：

首先獲取當前工作表中的數據范圍，然后遍歷每一行，在一維數組arr中存儲數據并以'|'符號將列名拼接起來作為key。再以字典對象的形式存儲數據，以第一個和第二個列名拼接的字符串作為新的key，將數據按著key分組。最后遍歷字典對象，將數據轉換成JSON格式的字符串并輸出。

總的來說，這個轉換的過程雖然比較繁瑣，但是只需要在VBA中編寫一次，在以后的使用中可以大大提高效率。