有大佬可以解释一下这段代码的意思吗 刚学习不太懂

Sub 明细到送货单()
Dim arr, brr, i&, j&, k&
s = [j2].Value
If Len(s) = 0 Then MsgBox "未输入订单号，无法查询": Exit Sub
arr = Sheet1.[a1].CurrentRegion
ReDim brr(1 To UBound(arr), 1 To 8)
For i = 1 To UBound(arr)
If arr(i, 1) = s Then
k = k + 1
If k = 1 Then [b3] = arr(i, 2): [e3] = arr(i, 3)
For j = 1 To 8
brr(k, j) = arr(i, j + 5)
Next
n = n + brr(k, 7)
End If
Next
[a7:j18] = ""
If k > 0 Then
i = 7
For i = i To i + k
Cells(i, 1) = brr(i - 6, 1)
Cells(i, 2) = brr(i - 6, 2)
Cells(i, "e") = brr(i - 6, 3)
Cells(i, "f") = brr(i - 6, 4)
Cells(i, "g") = brr(i - 6, 5)
Cells(i, "h") = brr(i - 6, 6)
Cells(i, "i") = brr(i - 6, 7)
Cells(i, "j") = brr(i - 6, 8)
Next i
[i19] = n
Else
MsgBox "查无数据"
End If
End Sub