If And Or

[padvou]

Could someone please post a working example of this scenario:
We have x,y,z
and we want to check with If statements whether a combination of their values exists:
if x is "" and y is "" or z is ""
If x is '' or x is 0 and y is ""

 

[lagore]

using standard mathematical notation re truth tables something like this should work, you just need to define what types x,y,& z are.

If (x = "" AND y = "") OR z = "" Then
      'your code
   End If
   
   If (x = "" OR x = 0) AND y = "" Then
      'your code
   End If

 

[padvou]

How about <> ?
Is it valid to check if a value "is not" something?
ex. if x <> "" ?

 

[sorex]

yes, that will work aswell.

 

[padvou]

! Thank you both for the prompt replies!
Kind regards

 

[padvou]

This scenario does not work:
x and y are all empty ""
if y="" and (x<>"" or x<>"0") then
...

 

[Erel]

This condition will always be true: (x<>"" or x<>"0") => x cannot be both "" and "0".

I guess that you meant: (x<>"" AND x<>"0")

 

[padvou]

The expression I wrote
if y="" and (x<>"" or x<>"0") then
...
is expressed correctly to reflect my intention, however it is not working at runtime. I tried it adding a level meaning:
if y="" then
if x <>"" then
if x <> "0" then
...
end if
end if
end if
This way it works.
It doesn't work when they are all expressed in a single line.

 

[thedesolatesoul]

You need to re-think your condition as Erel says above.

What does this statement mean:

(x<>"" or x<>"0")

If A = x <> "" : x is ANY string except for empty
If B = x <> "0" : x is ANY string except for 0

A OR B = x is ANY string.

So both your conditions re-include each other.

When you rewrite it as:

if y="" then
if x <>"" then
if x <> "0" then

it forms and AND condition i.e. x <> "" AND x <> "0"

 

[padvou]

You need to re-think your condition as Erel says above.

What does this statement mean:

(x<>"" or x<>"0")

If A = x <> "" : x is ANY string except for empty
If B = x <> "0" : x is ANY string except for 0

A OR B = x is ANY string.

So both your conditions re-include each other.

When you rewrite it as:

if y="" then
if x <>"" then
if x <> "0" then

it forms and AND condition i.e. x <> "" AND x <> "0"

A or B is not any string. It is any string except zero and empty, zero being a string here. Isn' it so?

 

[thedesolatesoul]

Look at what you wrote yourself here:

A or B is not any string. It is any string except zero and empty, zero being a string here. Isn' it so?

 

[sorex]

you should declare it as

if x is not "" and x is not "0"

so if (x<>"" and x<>"0") is valid since it will return a false when 1 statement if incorrect

in yours you have always a trigger been hit

x="0": if (x<>"" or x<>"0") here x is not "" but it is "0" so it returns true since 1 of both checks is correct

x="": if (x<>"" or x<>"0") here x is not "0" but it is "" so it returns true since 1 of both checks is correct

x="whatever": if (x<>"" or x<>"0") here x is not "0" and not "" so it returns true since both checks are correct

 

[Malky]

Or initiate it first?

if x = 0 then x ="" (or visa versa)?

Then do the test?

Malky