Elegant way to check variables before using them

[john_c]

I want to have a message box if var

Code: Select all

a != "aaa"

and var

Code: Select all

b != "bbb"

That is how I do it now:

Code: Select all

a := "111"
b := "222"

if (a != "aaa" and b != "bbb")
    MsgBox, Yes

The problem is, that in my real-life code var a is sometimes undefined. So, I don't want to see message box in this case, but it still appears:

Code: Select all

; a := "111" ; Commented line
b := "222"

if (a != "aaa" and b != "bbb")
    MsgBox, Yes ; Now I don't want this message box to be appeared, but it is till shown, despite the fact that var a is now undefined

That is my current way to fix this issue:

Code: Select all

; a := "111"
b := "222"

if ((a and b) and (a != "aaa" and b != "bbb"))
    MsgBox, Yes

But I don't like this way, because it seems too ugly. Is there more elegant way for it? i.e. I'm searching something like this:

Code: Select all

; a := "111"
b := "222"

IfAllVarsDefined
{
    if ((a and b) and (a != "aaa" and b != "bbb"))
        MsgBox, Yes ; This message box will not be shown now. Ant that is good.
}

[BoBo]

Code: Select all

a := "111"
b := "222"

if (a != "aaa") && (b != "bbb")
    MsgBox, Yes

Code: Select all

a := "aaa"
b := "222"

result := if (a != "aaa") && (b != "bbb") ? true : false
    MsgBox % result

[john_c]

Code: Select all

a := "111"
b := "222"

if (a != "aaa") && (b != "bbb")
    MsgBox, Yes

Code: Select all

a := "aaa"
b := "222"

result := if (a != "aaa") && (b != "bbb") ? true : false
    MsgBox % result

Hm, thanks for code, but it doesn't do the task. In both your examples, if one of vars is undefined, the message box is still shown. It should not be shown. (The message box should be shown only if both vars are defined).

[Soft]

Code: Select all

;a := 111
b := 222

If (StrLen(a) && StrLen(b))
{
	Msgbox, Won't be showed
}