quick question. [VB.net]

[Johanes]

can someone tell my what im doing wrong with this function??

 

Public Function checkOperation(ByVal n As String, ByVal x As Double, ByVal y As Double)

        If n Is "+" Then
            Return x + y
        ElseIf n Is "-" Then
            Return x - y
        ElseIf n Is "×" Then
            Return x * y
        ElseIf n Is "÷" Then
            Return x / y
        End If
    End Function

ive been looking at this for 30min now... still dont understand why its returning an error when i debug it...

 

Severity	Code	Description	Project	File	Line	Suppression State
Warning	BC42105	Function 'CheckOperation' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used.	BasicCalculator	C:\Users\pewpew\Google Drive\School Stuffs\Computer Prog\.Net Files\BasicCalculator\BasicCalculator\BasicCalcModule.vb	13	Active

this is the error warning

[Hoize]

can you post ethe error ?

 

[Johanes]

Severity	Code	Description	Project	File	Line	Suppression State
Warning	BC42105	Function 'CheckOperation' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used.	BasicCalculator	C:\Users\mah name\Google Drive\School Stuffs\Computer Prog\.Net Files\BasicCalculator\BasicCalculator\BasicCalcModule.vb	13	Active

here it is ^^

[minibois]

Is the error "function checkOperation does not allows return something"?

From what I can see, you have 4 things that could be happening for which you return something. But what if the input is not one of these 4 things? In such a case, nothing would be returned.

 

Usually in this case what you do is have a default value, like return an error value/0/whatever.

Easiest way to fix it now is by doing something like this:

int answer = 0;

If n Is "+" Then
  	answer = x + y
  ElseIf n Is "-" Then
  	answer = x - y
  ElseIf n Is "×" Then
  	answer = x * y
  ElseIf n Is "÷" Then
  	answer = x / y
End If
  
return answer;

 

With this setup you make a variable and fill that with info, in the different if's.

But what if none of these ifs get triggered? Well in that case, it will always return answer. with a 0 value.

[Hoize]

Sorry, I thought you were using Microsoft.NET. I cant helb you with VB.NET 

[Sauron]

It's not an error, it's a warning. It's warning you that if n isn't one of those 4 options the function won't return anything.

[Johanes]

1 minute ago, Sauron said:

It's not an error, it's a warning. It's warning you that if n isn't one of those 4 options the function won't return anything.

aaaaa.. i had an idea it was something like dat... damn you VB.net >.< thanks.. ill use @minibois solution for now ^^

[Johanes]

3 minutes ago, Hoize said:

Sorry, I thought you were using Microsoft.NET. I cant helb you with VB.NET 

its fine  atleast your helping in the forum