checking input from user

How to check the value entered by the user is a valid integer.For example: 2, 3,10 etc and not invalid value such as negative value(example:-3, -7, -10) or decimal value(example:0.14,3,1,-7,2,-0.4) or a character/special symbol (example: a, @,&, hi)

Answer 1

[Chad Greene]

To see if x is an integer greater than or equal to zero,

all([mod(x,1)==0 x>=0])

[pavikirthi]

Thanks,but I think its not working when the user inputs character like a, m, i etc, how to check for that?

[Chad Greene]

Ah, yes, I missed that part.

all([mod(x,1)==0 x>=0 isnumeric(x)])

[pavikirthi]

Thank you