How to say not equals to for 3 variables

I want to set the condition in my if loop for which , if a is not equal to b and not equal to c then do ... how do i do this a ~= b ~= c does not work

Answer 1

[John D'Errico]

How about:

a~=b && a~=c && b~=c

or...

numel(unique([a,b,c])) == 3

or many other ways.

[Avishka Karunaratne]

if i was to add another variable d , would the code then become

 numel(unique([a,b,c,d])) == 4

[Stephen23]

@Avishka Karunaratne: correct.

@John D'Errico: +1 for the nice answer.

[John D'Errico]

Yes. The nice thing about using unique here is it makes the test easy, for any number of variables.

Answer 2

[Azzi Abdelmalek]

a~=b & a~=c

%or you can use ismember function

~ismember(a,[b,c])

[John D'Errico]

Um, note that this answer fails, in the event that b and c were equal. For example, it does not catch the case where

a = 1;
b = 2;
c = 2;

As well, it has the problem that it does not use the short-circuited && operator, which is more efficient than the & operator.

[Avishka Karunaratne]

How do I do it then ?

[John D'Errico]

Read my answer as to how to do it. There I gave two ways of solving the problem that are NOT subject to failure.