这是作业。有人可以帮我弄清楚我声明的错误吗？当我给 Double 时，我总是出错

Question

Function quadratic (a As double, b As double, c As double) As Double
    Dim x,y As Double   

    if (a = 0) then
        Console.Writeline("no solution for a = 0")      
    else if 
            ((b * b - 4 * a * c) <0)
            Console.Writeline("no real solutions")          
    else
            x = ((- b + Math.Sqrt(b * b - 4 * a * c)) / ( 2 * a))
            y = ((- b - Math.Sqrt(b * b - 4 * a * c)) / ( 2 * a))

            if (x > y) then
                Console.Writeline(x)
            else 
                Console.Writeline(y)
            End if 
    End if
End Function

Answer 1

我不会为你检查你的数学:-)但是如果你改变这个:

else if 
  ((b * b - 4 * a * c) <0)
  Console.Writeline("no real solutions")

为此：

ElseIf ((b * b - 4 * a * c) < 0) Then
  Console.Writeline("no real solutions")

编译运行...