How to check the type of input

How would I be able to check for the correct input value for a function, say I'm expecting a number but instead they put in a character?

Answer 1

[Mischa Kim]

Sarah, use the isnumeric command (see example here). Or use validateattributes as a more advanced concept.

Answer 2

[Azzi Abdelmalek]

Use class function

s='err'
class(s)