问题
I want a regular expression that accept only alphabets,hyphen,apostrophe,underscore. I tried
/^[ A-Za-z-_']*$/
but its not working. Please help.
回答1:
Your regex is wrong. Try this:
/^[0-9A-Za-z_@'-]+$/
OR
/^[\w@'-]+$/
Hyphen needs to be at first or last position inside a character class to avoid escaping. Also if empty string isn't allowed then use + (1 or more) instead of * (0 or more)
Explanation:
^ assert position at start of the string
[\w@'-]+ match a single character present in the list below
Quantifier: Between one and unlimited times, as many times as possible
\w match any word character [a-zA-Z0-9_]
@'- a single character in the list @'- literally
$ assert position at end of the string
回答2:
Move the hyphen at the end or the beginig of the character class or escape it:
^[ A-Za-z_'-]*$
or
^[- A-Za-z_']*$
or
^[ A-Za-z\-_']*$
If you want all letters:
^[ \pL_'-]*$
or
回答3:
When using a hyphen in a character class, be sure to place it at the end of the character class as a best practice.
The reason for this is because the hyphen is used to signify a range of characters in the character class, and when it is at the end of the class, it will not create any ranges.
回答4:
My best bet would be :
/[A-Za-z-\'_@0-9]+/g
回答5:
You can use the following (in Java):
String acceptHyphenApostropheUnderscoreRegEx = "^(\\p{Alpha}*+((['_-]+)\\p{Alpha})?)*+$";
If you want to have spaces and @ also (as some have given above) try:
String acceptHyphenApostropheUnderscoreRegEx = "^(\\p{Alpha}*+((\\s|['@_-]+)\\p{Alpha})?)*+$";
来源：https://stackoverflow.com/questions/21677535/regular-expression-for-alpahbet-underscore-hyphen-apostrophe-only