x is a vector of unknown length
your function should return the index of the first element in the vector that is greater than 6. If all elements in x are less than 6, the function should return 'none'
example: x = [1 2 7 2 3 2 4 8 6]
output = 3
From a usability point of view, returning a string to indicate nothing found is probably the worst. an empty value or 0 would be much better.
Guillaume, I would say that that depends upon the intended 'audience' for the output.