I am trying to allow '-' in the regular expression for telephone numbers, but the - is usually used for ranges (e.g. A-Z). So how do I allow just the character? I tried escapting using /-, but that's not working.
$reg_num = "/[^0-9+ ()]/";
You need to escape it with a backslash \. So it should be written as \-.
Write it in the end instead of '-' being between two characters.
Very simplified example:
[0-9-] would match 099-2233-3333 where 0-9 is a range, and the - in the end is a seperate dash sign to match.
Put it first in the range, like [^-0-9+ ()]. The hyphen needs to separate two characters to define a range; if it isn't (in this case because the ^ is also interpreted as a modifier, not a character in the set), then it's just a character in the set like any other.
escaping using \-
\
is escape character!
Related
$.validator.addMethod('AZ09_', function (value) {
return /^[a-zA-Z0-9.-_]+$/.test(value);
}, 'Only letters, numbers, and _-. are allowed');
When I use somehting like test-123 it still triggers as if the hyphen is invalid. I tried \- and --
Escaping using \- should be fine, but you can also try putting it at the beginning or the end of the character class. This should work for you:
/^[a-zA-Z0-9._-]+$/
Escaping the hyphen using \- is the correct way.
I have verified that the expression /^[a-zA-Z0-9.\-_]+$/ does allow hyphens. You can also use the \w class to shorten it to /^[\w.\-]+$/.
(Putting the hyphen last in the expression actually causes it to not require escaping, as it then can't be part of a range, however you might still want to get into the habit of always escaping it.)
The \- maybe wasn't working because you passed the whole stuff from the server with a string. If that's the case, you should at first escape the \ so the server side program can handle it too.
In a server side string: \\-
On the client side: \-
In regex (covers): -
Or you can simply put at the and of the [] brackets.
Generally with hyphen (-) character in regex, its important to note the difference between escaping (\-) and not escaping (-) the hyphen because hyphen apart from being a character themselves are parsed to specify range in regex.
In the first case, with escaped hyphen (\-), regex will only match the hyphen as in example /^[+\-.]+$/
In the second case, not escaping for example /^[+-.]+$/ here since the hyphen is between plus and dot so it will match all characters with ASCII values between 43 (for plus) and 46 (for dot), so will include comma (ASCII value of 44) as a side-effect.
\- should work to escape the - in the character range. Can you quote what you tested when it didn't seem to? Because it seems to work: http://jsbin.com/odita3
A more generic way of matching hyphens is by using the character class for hyphens and dashes ("\p{Pd}" without quotes). If you are dealing with text from various cultures and sources, you might find that there are more types of hyphens out there, not just one character. You can add that inside the [] expression
$.validator.addMethod('AZ09_', function (value) {
return /^[a-zA-Z0-9.-_]+$/.test(value);
}, 'Only letters, numbers, and _-. are allowed');
When I use somehting like test-123 it still triggers as if the hyphen is invalid. I tried \- and --
Escaping using \- should be fine, but you can also try putting it at the beginning or the end of the character class. This should work for you:
/^[a-zA-Z0-9._-]+$/
Escaping the hyphen using \- is the correct way.
I have verified that the expression /^[a-zA-Z0-9.\-_]+$/ does allow hyphens. You can also use the \w class to shorten it to /^[\w.\-]+$/.
(Putting the hyphen last in the expression actually causes it to not require escaping, as it then can't be part of a range, however you might still want to get into the habit of always escaping it.)
The \- maybe wasn't working because you passed the whole stuff from the server with a string. If that's the case, you should at first escape the \ so the server side program can handle it too.
In a server side string: \\-
On the client side: \-
In regex (covers): -
Or you can simply put at the and of the [] brackets.
Generally with hyphen (-) character in regex, its important to note the difference between escaping (\-) and not escaping (-) the hyphen because hyphen apart from being a character themselves are parsed to specify range in regex.
In the first case, with escaped hyphen (\-), regex will only match the hyphen as in example /^[+\-.]+$/
In the second case, not escaping for example /^[+-.]+$/ here since the hyphen is between plus and dot so it will match all characters with ASCII values between 43 (for plus) and 46 (for dot), so will include comma (ASCII value of 44) as a side-effect.
\- should work to escape the - in the character range. Can you quote what you tested when it didn't seem to? Because it seems to work: http://jsbin.com/odita3
A more generic way of matching hyphens is by using the character class for hyphens and dashes ("\p{Pd}" without quotes). If you are dealing with text from various cultures and sources, you might find that there are more types of hyphens out there, not just one character. You can add that inside the [] expression
I have a regular expression that allows only specific characters from the name fields in an HTML form, namely letters, white space, single quotes, hyphens and periods. Here is the pattern:
return mb_ereg_match("^[\w\s'-\.]+$", $name);
Problem is this pattern, for some reason, returns true when there are literal asterisks in $name. This shouldn't be possible unless I'm missing something. I've done multiple searches on literal asterisks and all I found was the "\*" pattern for intentionally matching them.
The same pattern in preg_match() also returns a match when passed a string like "*John".
What the heck am I missing?
You need a double-backslash in front of these codes. One to escape the backslash, one to escape the escape sequence.
You also need to escape the -, otherwise it accepts all characters "between" ' and ..
return mb_ereg_match("^[\\w\\s'\\-\\.]+$", $name);
Have a look at a working case (using preg_match): http://ideone.com/E8afAM
When enclosed in square-brackets, the hyphen acts as a special character to denote a range. In your case, it's matching all characters in the range ' to ..
Escaping the hyphen should return the desired result:
^[\w\s'\-\.]+$
I have a regular expression that allows only specific characters from the name fields in an HTML form, namely letters, white space, single quotes, hyphens and periods.
You miss, that \w is not a letter character. php.net says:
A "word" character is any letter or digit or the underscore character, that is, any character which can be part of a Perl "word".
And, the perl definition is:
A \w matches a single alphanumeric character (an alphabetic character, or a decimal digit) or a connecting punctuation character, such as an underscore ("_").
The connecting punctuation character should mean only _ as i read, but this is maybe a multibyte extension's bug.
If you use mb_ereg_match only for whole unicode matches, give a try to preg_match's /u modifier & the Unicode character properties feature, since php 5.1.0
I am trying to validate that the given string contains contains only letters, numbers, spaces, and characters from a set of symbols (!-?():&,;+). Here is what I have so far:
/^[a-zA-Z0-9 !-?\(\):&,;\+]+$/
Now this works somewhat but it accepts other characters as well. For example, strings containing * or # validate. I thought that the ^ at the beginning of the expression and the $ at the end meant that it would match the whole string. What am I doing wrong?
Thanks.
/^[a-zA-Z0-9 !-?\(\):&,;\+]+$/
The - is not nice where you placed it! If you want to place - inside a character class be sure to either place it first or last e.g.
/^[a-zA-Z0-9 !?\(\):&,;\+-]+$/
Otherwise it will take the range of ! until ? whatever this range maybe...Depends on your regex machine.
Finally special characters are not special inside character classes. So no need to escape most of them :
/^[a-zA-Z0-9 !?():&,;+-]+$/
You have specified a "range" within your character class:
[!-?]
Means all ASCII symbols between ! and ?
http://www.regular-expressions.info/charclass.html
You need to escape the minus - with a \ backslash. (OTOH the backslash is redundant before the + and ( and ) within a character class.)
I'm working in php and want to set some rules for a submitted text field. I want to allow letters, numbers, spaces, and the symbols # ' , -
This is what I have:
/^(a-z,0-9+# )+$/i
That seems to work but when I add the ' or - symbols I get errors.
Almost there. What you're looking for is called character classes. These are denoted by the use of square brackets. For example
/^[-a-z0-9+#,' ]+$/i
To include the hyphen character, it needs to be the first or last character in the class.
Edit
As you want to include the single quote and you're using PHP where regular expressions must be represented as strings, be careful with how you quote the pattern. In this case, you can use either of
$pattern = "/^[-a-z0-9+#,' ]+\$/i"; // or
$pattern = '/^[-a-z0-9+#,\' ]+$/i';
You should use a character class - [a-zA-Z0-9 #',-]
Note that - should be used first or last or escaped otherwise it gets treated as denoting a range and you will get errors
I want to allow letters, numbers, spaces, and the symbols #, ', , and -.
Use this regex...
/^[-a-zA-Z\d ',#]+\z/
Note the \z. If you use $, you are allowing a trailing \n. CodePad.
Ensure to escape the ' if you are using ' as your string delimiter.
Please use /^[a-z,0-9+\#\-,\s]+$/i
Use this regex:
/^[-a-z0-9,# ']+$/i