Im quite bad at figuring out regular expressions for things that I need to search for.
I have this field in the format of ########-#.
The issue here is that there could be a maximum of 10 numbers in front of the 'dash' and between one to two numbers after the 'dash'.
How can I possibly achieve this in just regular expressions ?
Can I just do \d{5,}-\d{1,} ? Which says that you need at least 5 numbers in front of the dash and at least 1 after the dash ? If I do this in js do I need a special character for dash ?
Thanks in advance.
Specify your quantities using the {min,max} quantifier:
/\d{,10}-\d{1,2}/
You do not need to escape the - since it has no special meaning outside of character classes.
var m = /(\d{0,10})-(\d{1,2})/
m[1] = // first set of numbers
m[2] = // second set
An expression like this would work:
\d{1,10}-\d{1,2}
This will match 1 to 10 digits, followed by a dash, followed by one or two additional digits.
Of course, you can replace the first quantifier with {0,10} or {,10} if you want the first set of digits to be entirely optional.
You need to use quantifiers. Something like this will work
[0-9]{1,10}-[0-9]{1,2} or [0-9]{0,10}-[0-9]{1,2} if possible
Related
Pardon my inexperience in Regex world.
I am trying to validate a expression which look like this : AB-4567 or PK-1234.
i.e. either set of 2 fix letters followed by a '-' and then digits with no constrain on length.
Few more valid examples:
AB-1234
AB-12
AB-54643564
PK-1
PK-341313
PK-133
So, it should start with either AB or PK then without any space hyphen and then any length of digits
I tried with /(AB)|(PK)[-][0-9]/ but it fails in following situation
ABPK-1213 (both set of prefix)
AB-R12U45N (alphabets in digits. either at start, middle or end)
I know I am missing something very basic but not able to solve it.
For the first six examples
/^(AB|PK)-[0-9]+$
If you want to include the other two possibility (ABPK-1213 , AB-R12U45N) try
/^(AB|PK|ABPK|PKAB)-[0-9A-Z]+$
You were almost there:
^(?:AB|PK)-[0-9]+$
Your alternation character | was in the wrong place. The way you had it, it meant "match AB OR match PK and all these other characters.
I'm relative new to RegEx and I've encountered a problem. I want to regex a name. I want it to be max 100 characters, contain at least 2 alphabetic characters and it will allow the character '-'.
I have no problem to only check for alphabetic characters or both alphabetic characters and hyphen but I dont't want a name that potantially can be '---------'.
My code without check for hyphens is
var nameRegExp = /^([a-z]){2,100}$/;
An explanation for the code is appreciated as well.
Thanks!
I guess
/^(?=.*[a-z].*[a-z])[a-z-]{1,100}$/
the lookahead part (^(?=.*[a-z].*[a-z])) checks if there are at least two letters. This pattern ("start of string, followed by...") is a common way to express additional conditions in regexes.
You can limit the number of - by adding a negative assertion, as #Mike pointed out:
/^(?=.*[a-z].*[a-z])(?!(?:.*-){11,})[a-z-]{1,100}$/ // max 10 dashes
however it might be easier to write an expression that would match "good" strings instead of trying to forbid "bad" ones. For example, this
/^[a-z]+(-[a-z]+)*$/
looks like a good approximation for a "name". It allows foo and foo-bar-baz, but not the stuff like ---- or foo----bar----.
To limit the number of - you could add a negative look-ahead, where the number 3 is one more than the maximum number you want to allow
/^(?!(?:[a-z]*-){3,})(?=-*[a-z]-*[a-z])[a-z-]{2,100}$/
I'm trying to match a string using regex (of which I am new to) but I can't get it to match.
These should be accepted:
GT-00-TRE
KK-10-HUH
JU-05-OPR
These should not:
HTH-00-AS
HM-99-ASD
NM-05-AK
So the pattern goes 2 letters, hyphen, 2 digits (between 00 and 11 inclusive), hyphen, 3 letters.
So far the best I can come up with is:
var thePattern = /^[a-z]{2}[-][00-11][-][a-z]{3}$/gi;
I can't help but feel that I'm pretty close.
Can anyone give me any pointers?
Thanks.
This should be what you need:
var thePattern = /^[a-z]{2}[-](0\d|1[0-1])[-][a-z]{3}$/gi;
In order to do a range 00-11, you have to say "(0 followed by 0-9) or (1 followed by 0 or 1)". This is because specifying a range within [] only works for single digits. Luckily your case is pretty simple, otherwise it could get quite complex to work around that.
Your regex is OK, but for one thing: the digits matching is a bit more complex
(0\d|10|11)
you want to match a zero followed by a digit (\d) OR (|) a ten OR a eleven.
Something in square brackets represents just a single character in a range. [0-5] means any single digit between 0 and 5, [a-q] means any lowercase letter from a to q. There's no such thing as [00-11] because it would require to work on more than one character at a time.
Can anyone give me the regular expression for currency which have the following formats :
1000 - valid
1,000 - valid
1,000.00 or 1000.00 - valid.
This means, the number May or May Not contain a comma(,) separator every 3 digits.
The number May Or May Not contain a dot (.), and if it carries a dot(.) it should show atleast 1 number after the decimal place.
And lastly it should be numerical characters only. If I need to make my question clear kindly suggest.
/^\d{1,3}(?:(?:,\d{3})*|(?:\d{3})*)(?:\.\d{1,2})?$/
"Between one and three digits, then any number of groups of three digits prefixed by a comma or any number of groups of three digits not prefixed by said comma (disallowing a mix of the two kinds of groups), then an optional group of one or two digits prefixed by a dot."
Note: This regex assumes that you want to validate an entire string against the criteria outlined in your question. If you want to use it to find such numbers in a longer string, you will need to remove the ^ and $ from the beginning and end of the expression.
Something like so should work: (,?\d{3})+(\.\d{2})?. The regex will attempt to match a sequence of 3 digits precedeed by an optional comma, which is then, finally followed by an optional decimal point and 2 digits.
Please refer to this tutorial for more information.
EDIT: As per the comment below, the above regex can fail. I would recommend first using this regular expression: ^[\d][\d.,]+$ to make sure that you only have digits, thousand and decimal seperators. This regular expression will also make sure that the number starts with a digit, not with anything else. You could most likely have one regular expression which does everything, but it will most likely be quite complex.
I was surfing online for date validation, but didn't exactly understand the regex. Can anyone explain it? I'm confused with ?, {} and $. Why do we need them?
dateReg = /^[0,1]?\d{1}\/(([0-2]?\d{1})|([3][0,1]{1}))\/(([1]{1}[9]{1}[9]{1}\d{1})|([2-9]{1}\d{3}))$/;
? means “zero or one occurences”.
{x} (where x is a number) means “exactly x occurences”
$ means “end of line”
These are very basic regex, I recommand you to read some documentation.
^ = beginning of the string
[0,1]? = optional zero, one or comma (the comma is probably an error)
\d{1} = exactly one digit (the {1} is redundant)
\/ = a forward slash
[0-2]? = optional zero, one or two (range character class) followed by any single digit (\d{1})
OR [3] = three (character class redundant here) followed by exactly one zero, one or comma
\/ = forward slash
[1]{1}[9]{1}[9]{1}\d{1} = 199 followed by any digit
OR 2-9 followed by any 3 digits
Overall, that's a really poorly written expression. I'd suggest finding a better one, or using a real date parser.
In Javascript you could validate date by passing it to Date.Parse() function. Successful conversion to a date object means you have a valid date.
Wouldn't recommend using regex for this. Too many edge cases and code gets hard to maintain.
? means "Zero or one of the aforementioned"
{n} means "exactly n of the aforementioned"
$ is the end of the String (Thanks #Andy E)
To summarize briefly:
`?' will match 0 or 1 times the pattern group you put in front of it. In this case, it's possibly being misused and should be left out, but it all depends on just what you want to match.
`{x}' tells the regex to match the preceding pattern group exactly x times.
`$' means to match the end of the line.
Well:
^ // start of the text
$ // end of the text
X{n} // number n inside these curly parenthesis define how many exact occurrences of X
X{m,n} // between m to n occurrences of X
X? // 0 or 1 occurrence of X
\d // any digits 0-9
For more help about Javascript date validation please see: Regular Expression to only grab date