MATLAB: How can use “is not equal to” command in matlab? and how terminate or cancel if else?

Question

if i want to restrict variable

length(a) "is not equal to" length(b);
length(c) "is not equal to" length(a);
then terminate 
end

Answer 1

E.g.,

if( length(a) ~= length(b) || length(c) ~= length(a) )
    % terminate
end

For the terminate statement, you need to be more clear. If you are terminating a loop of some sort, then

      break;

If you are terminating a function with an error return, then

      error('Lengths are not equal');

If termination means something else, then you need to tell us.