Is there a way to limit a regular expression to 100 characters with a regular expression?
\[size=(.*?)\](.*?)\[\/size]
So Look at me! wouldn't work.
I want to limit the numbers, only allow numbers between 1 and 100.
Is there a way to limit a regex to 100 characters WITH regex?
Your example suggests that you'd like to grab a number from inside the regex and then use this number to place a maximum length on another part that is matched later in the regex. This usually isn't possible in a single pass. Your best bet is to have two separate regular expressions:
one to match the maximum length you'd like to use
one which uses the previously extracted value to verify that its own match does not exceed the specified length
If you just want to limit the number of characters matched by an expression, most regular expressions support bounds by using braces. For instance,
\d{3}-\d{3}-\d{4}
will match (US) phone numbers: exactly three digits, then a hyphen, then exactly three digits, then another hyphen, then exactly four digits.
Likewise, you can set upper or lower limits:
\d{5,10}
means "at least 5, but not more than 10 digits".
Update: The OP clarified that he's trying to limit the value, not the length. My new answer is don't use regular expressions for that. Extract the value, then compare it against the maximum you extracted from the size parameter. It's much less error-prone.
If you want to restrict valid input to integer values between 1 and 100, this will do it:
^([1-9]|[1-9][0-9]|100)$
Explanation:
^ = start of input
() = multiple options to match
First argument [1-9] - matches any entries between 1 and 9
| = OR argument separator
Second Argument [1-9][0-9] - matches entries between 10 and 99
Last Argument 100 - Self explanatory - matches entries of 100
This will not accept:
Zero - 0
Any integer preceded with a zero - 01, 021, 001
Any integer greater than 100
If you want numbers from 1 up to 100:
100|[1-9]\d?
Limit the length of characters in a regular expression:
^[a-z]{6,15}$'
Limit length of characters or numbers in a regular expression:
^[a-z | 0-9]{6,15}$'
(^(\d{2})|^(\d{4})|^(\d{5}))$
This expression takes the number of length 2,4 and 5. Valid Inputs are
12
1234
12345
You could do a negative lookahead for the number of characters you want. So if you have a complex regex to get a specific format and you wanted to limit it to say, 50 characters. Then you could preface it with:
(?!.{51})
Related
I have a string containing a sequence of 1s and 0s. I need to define a regular expression such that no sequence of consecutive 1s can be longer than a variable max or shorter than a variable min. How would I go about this? Pretty new to regex.
Edit: Examples
If min were 2 and max were 4 the regex would accept:
110000111011110
and would not accept:
111110000000000 or 000010000100000
To make this simple, assume max=7 and min=3.
^0*(1{3,7}(0+|$))*0*$
See live demo.
This is an example regex to validate consecutive 1s min 3 to max 7 times:
^(?!.*1{8})(?!(^|.*0)1{1,2}(0|$))
Explanation:
^ - anchor at start of string
(?!.*1{8}) - negative lookahead for a sequence of 8+ 1s
(?!(^|.*0)1{1,2}(0|$)) - negative lookahead for sequence of up to 2 1s, preceded either by start of string or 0, and suffixed by either a 0 or end of string
I'm looking for a regular expression for any number from 1-60, here's what I have so far:
[0-6][0-9]
Super simple. When I input a number like 950, it catches the 50, ignores a 9 is in front.
Thanks in advance.
\b([1-9]|[1-5]\d|60)\b
You have to encapsulate it in word breaks (\b) to ensure parts of a number aren't matched (like 950).
The idea is to either match a single digit number - 1 to 9 inclusive ([1-9]), or (|) a two digit number, where the first digit is between 1 and 5 inclusive ([1-5]\d), or 60 itself.
I need a regular expression that will allow me to enter a specific set of characters.
The regular expression should not allow me to enter numeric values only unless the numeric value entered is prefix with '9999'.
It should also not allow me to enter any string of data if it contains any letter pass "F" from the alphabet.
And lastly, the length of the value entered should not exceed 12 characters/digits
Is the above possible?
I have a regular expression that will take care of the length and numeric values only but I need assistance with the prefix and letters pass "F".
^(?![0-9]*$)[a-zA-Z0-9]{12}$
Valid Samples:
3847a654b321
3899c654b876
999946578432
999975620983
Invalid Samples:
874k459m8723
546p34s85734
543216789012
243567890218
Hope this helps.
Brief
Based on the following information:
All digits, must begin with 9999 or digits and characters in the a-f range only
Max length of 12 characters
Code
This is the regex you're looking for:
See this regex in use here
^(?:9{4}\d{8}|(?=.*[a-f].*)[\da-f]{12})$
Explanation
Assert position at start of line/string
Match 4 9s followed by 8 of any digit OR ensure there is a character in the a-f range ahead and ensure it's made up of 12 of any digit or character in the a-f range
Assert position at end of line/string
Split the regex in two cases:
^(9999[0-9]{8})|((?=.*[0-9])(?=.*[a-fA-F])([a-fA-F0-9]{12}))$
\------------/ \------------------------------------------/
1 2
Numeric values that start with 9999
Values that contain at least one character between A and F and numbers
I want to make a string pattern that is:
at least 7 characters long
have at least 1 digits, max 5
have at least 3 capital alphabetic characters , max 5
have at least 1 lower alphabetic characters , max 5
have at least 1 special characters , max 5
How to express this in a regular expression?
I can do something like
^((?=.*[A-Z]{3,5})(?=.*[a-z]{1,5})(?=.*[0-9]{1,5})(?=.*[.~!##$%^_&-]{1,5}))(?=.{7,20}).*$
I don't want to require this kind of order. In fact, any mixed order should be accepted, only require the number of characters.
This Match:
PASSW120P45ccb^&#%#
But this one does not
PA12S1SW2045ccb^&#%#
How can i fix this?
P&#Ass120W45ccb^%#
P&#Ass20W45cb^%#
Please have a look at https://regex101.com/r/vF2yO7/51
You need to operate with the contrary character classes, put these into non-capturing groups and repeat these:
^
(?=(?:\D*\d){1,5})
(?=(?:[^A-Z]*[A-Z]){3,5})
(?=(?:[^a-z]*[a-z]){1,5})
(?=(?:[^.\~!##$%^_&-]*[.\~!##$%^_&-]){1,5})
.{7,20}
$
See a demo on regex101.com.
The structure here is always the same, e.g. with the numbers: require anything not a number zero or more times, followed by a number and repeat the whole pattern 1-5 times. In general:
(?=(?:not_what_you_want*what_you_want){min_times, max_times})
In the expression above, all pos. lookaheads follow this scheme, [^...] negates the characters to be matched in the class and \D* is essentially the same as [^\d]*.
I have this regularexpression
[0-9]+(,[0-9][0-9]?)?
it matches on 345563,24 but how can I limit the left side part on 8 characters?
88888888,00 - true because 8 characters
999999999,00 - false because 9 characters
Use this:
[0-9]{0,8}(,[0-9][0-9]?)?
{m,n} indicates the minimum and maximum number of occurrences of the previous character/group. You can indicate just a minimum or just a maximum by leaving one side of the expression blank. So the expression above would allow 0 to 8 occurrences of a digit. If you want 1 to 8 occurrences of a digit at the beginning of your expression, use this:
[0-9]{1,8}(,[0-9][0-9]?)?
I would do :
^[1-9][0-9]{,7}(,[0-9][0-9]?)?$
number (10,2) would be matched
empty string won't be matched
first digit should not be 0 (zero)
Borrowing elements from the answers of both #Kent and #user1775603, I'd try the following:
^([1-9][0-9]{0,7}|0)(,[0-9][0-9])?$
This will match:
any up-to-eight-digits number starting with a nonzero, with zero or two decimal digits after the comma
any number >= 0 and < 1 with zero or two decimals after the comma (matching 0,xx where x are digits)
Do note that the decimal separator, unless you take care to do otherwise, is very often locale-dependent. Exactly how to counteract this depends on what language and/or framework you are working with, but it's something to watch out for.
I would recommend \b instead of ^ and $ as in:
\b([1-9][0-9]{0,7}|0)(,[0-9][0-9]?)?\b
So that the input does not need to be fed alone and can be found in the middle of a large text too.