Regex: Number Range Excluding Specific Number

Exclude certain numbers from range of numbers using Regular expression

Described in more detail in this answer, you can use the following regex with the “Negative Lookahead” command ?!:

^((?!501|504)[0-9]*)$

You can see the regex being executed & explained here: https://regex101.com/r/mL0eG4/1

/^((?!501|504)[0-9]*)$/mg
^ assert position at start of a line
1st Capturing group ((?!501|504)[0-9]*)
(?!501|504) Negative Lookahead - Assert that it is impossible to match the regex below
1st Alternative: 501
501 matches the characters 501 literally
2nd Alternative: 504
504 matches the characters 504 literally
[0-9]* match a single character present in the list below
Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
0-9 a single character in the range between 0 and 9
$ assert position at end of a line
m modifier: multi-line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
g modifier: global. All matches (don't return on first match)

RegEx: number range excluding specific number

You may use a negative lookahead assertion in your regex:

~\bAM19/0(?!803)[678]\d{2}\b~

RegEx Demo

Here we have a negative lookahead (?!803) after matching 19/0 which will fail the match if 803 appears right after 19/0 in input.

Also note that by using an alternate regex delimiter ~ you can avoid escaping / in your regex.

Regex to exclude a range of numbers

Thank you for the answers (which all work correctly).

Bohemian was also correct in saying that:

it ends with \.* but should end with \..* or more precisely \.\d*

So I edited my regular expression to the following which now works fine:

([0-9][0-9]\.\d*)|(1[0-9][0-9]\.\d*)

0-100 number range regex excluding 1 and 3

Detect any given number in the range of 0 to 100 , however excluding 1 and 3

^(?!(?:1|3)$)(?:[0-9]{1,2}|100)$

See demo

In case the numbers are not standalone strings:

\b(?!(?:1|3)\b)(?:[0-9]{1,2}|100)\b

See another demo

The main point here is a look-ahead in the beginning, anchors (\b word boundary, ^ start and $ end of string) and the character classes with limiting quantifiers.

The (?!(?:1|3)$) lookahead makes sure the match fails if a 1 or (|) 3 appears right after the start of string (^) and before the end of string ($) (or between word boundaries as in the second example).

The [0-9]{1,2} character class matches 1 or 2 digits (due to a limiting quantifier {1,2}) from 0 to 9.

How to match range of numbers excluding first digit

This regex enforces the uniqueness of X, Y and Z:

([1-9])((?!\1)[1-9])\10((?!\1|\2)[1-9])\3\2

...but there's no way to enforce their ordering with a regex.

About the regex:

([1-9]) captures the first digit in group #1. That's the first X in your template.

((?!\1)[1-9]) captures the second digit in group #2, but only after the negative lookahead confirms that it isn't the same as the first digit. That's the Z value.

\1 matches the third digit, assuming it's the same as the first digit.

0 is obvious

((?!\1|\2)[1-9]) represents the Y value, so we have to confirm that it's not the same as either of the other two captures. It's captured in group #3.

\3 matches the same digit again; that's the second Y.

\2 matches another of whatever the Z value was, and Bob's your uncle!

Getting back to that 0 again, there's one caveat that I overlooked. If there happen to be ten or more capturing groups in the regex, \10 could be interpreted as a backreference to group #10. It's a good idea to break up that kind of thing whether it needs it or not.

Many regex flavors provide alternative notation that isolates the group reference, like \g<1> or ${1}. Not knowing what flavor you're using, I'll use square brackets to isolate the zero instead (i.e., turn it into a single-element character class):

([1-9])((?!\1)[1-9])\1[0]((?!\1|\2)[1-9])\3\2

Excluding some character from a range - javascript regular expression

To exclude k or p from [a-zA-Z] you need to use a negative lookahead assertion.

(?![kpKP])[a-zA-Z]+

Use anchors if necessary.

^(?:(?![kpKP])[a-zA-Z])+$

It checks for not of k or p before matching each character.

^(?!.*[kpKP])[a-zA-Z]+$

It just excludes the lines which contains k or p and matches only those lines which contains only alphabets other than k or p.

DEMO

Exclude a certain number from this regex

A negative look-ahead assertion can do this for you

/^(?!2$)([a-zA-Z,\d]){1,5}$/

Regular expression to exclude number from list

If negative lookaheads be allowed, then you can try the following regex:

^(?!(?:1|4|10)$)\d+$