計算 1 + 2 + ... + n =?

 

 

Module Module1

    Sub Main()
        Dim a As Long
        Dim N As Long
        N = InputBox("請輸入N值")
        For i As Long = 1 To N
            a = a + i
        Next
        Console.WriteLine(a)
        Console.ReadLine()
    End Sub

End Module