问题
I'm using regex to validate username
^[a-zA-Z]+\.[a-zA-Z]{4,10}^'
Unfortunately it doesn't affect if the the value contains special characters such as !@#$%^&*)(':;
I would glad to get some help for Regex that contains:
- Alphanumeric only (
a-zA-Z0-9) - Length between 4 - 10 characters.
回答1:
The conditions you specified do not conform to the regexp you posted.
the regexp you posted ^[a-zA-Z]+\.[a-zA-Z]{4,10}^ is erroneous I guess, because of the ^ in the end, it will never be matched to any expression, if you want to match with the ^ at the end of the expression, you need to escape it like this \^. but ^ alone means "here is the start of the expression", while $ means "here is the end of the expression".
Even though, it denotes:
- It starts with alpha (at least 1).
- there must be a '.' period character.
- Now there must be at least 4 alphas.
The regexp you need is really is:
^[a-zA-Z0-9]{4,10}$
This says:
- It starts with alphanumeric.
- There can be minimum of 4 and maximum of 10 of alphanumeric.
- End of expression.
回答2:
Try this:
^[a-zA-Z0-9]{4,10}$
来源：https://stackoverflow.com/questions/6814780/regex-without-special-characters