Regex matches but shouldn't

Question

This is my code that checks if there are only alphanumeric characters filled in, but when i enter something like adasd@#$ it still matches and i have no idea why. Any idea how t

Answer 1

What you have matches any string that contains one letter or number somewhere in it.

You need to add anchors to the beginning and end of the string (^ and $), as well as a + to allow for more than one character:

"^[0-9a-zA-Z]+$"

This means "the entire string must be made of letters and numbers".

The + also requires that there is at least one character in the string. This is probably a good thing, but if you want to match empty strings, as well, you can change it to *.