章末問題７−３の解答例

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim i As Integer
        Dim 合計 As Double
        合計 = Val(預金額.Text)
        For i = 1 To Val(年後.Text)
            合計 = 合計 * (1 + Val(利子.Text) / 100)
        Next
        年後の預金額.Text = Format(合計, "\\#,#.00")

        i = 0
        合計 = Val(預金額.Text)
        Do While 合計 <= Val(目標金額.Text)
            合計 = 合計 * (1 + Val(利子.Text) / 100)
            i = i + 1
        Loop
        目標達成年.Text = i
    End Sub