Dim F As Worksheet, R As Range, TE(), TS(), L As Long
Set F = Worksheets("zaza")
Set R = F.[A1].Resize(F.[A65000].End(xlUp).Row, 4)
TE = R.Value
ReDim TS(1 To UBound(TE, 1), 1 To 1) ' si vider les vides,
TS = R.Columns(2).Value ' si garder les anciens devenus vides.
For L = 1 To UBound(TE, 1)
If TE(L, 1) <> "" Then TS(L, 1) = TE(L, 2) + TE(L, 4)
Next L
R.Columns(2).Value = TS