regexp pattern to match alphanumeric strings without initial spaces

Question

i have input pattern setted like this: pattern="[a-zA-Z0-9]+"

When i type a space in the input, it returns me a error message ( which is good ).

But, when i type mi full name, for e.g. Jhonatan Sandoval, it does too.

How can i sett the pattern only with no spaces before the name?

Answer 1

That will work as you expect:

pattern="[a-zA-Z0-9][a-zA-Z0-9 ]+"