I want to validate my currency field with regex. I want to allow the following pattern entries
1.23
1
.45
0.56
56.00
No comma should be allowed. I've tried \d+(\.\d\d) but it allows only first, fourth and fifth entries. \d+(?:\.\d\d+)? allows all but third one.
Use \d* instead of \d+ before the decimal to match zero or more digits. Also add anchors (^ and $) or else it will pass as long as there is any match available. This would also validate an empty string, so if necessary you can use a lookahead to make sure there is at least one digit:
^(?=.*\d)\d*(?:\.\d\d)?$
Regexes for floating-point numbers are a solved problem:
\d*\.?\d+
For at least two decimals:
(\d*\.\d)?\d+
To make it more comprehensible:
\d+|\d*\.\d{2,}
And for exactly two decimals:
\d+|\d*\.\d{2}
Depending on your language, don't forget to anchor the expression so that it must match the whole string.
Related
I want to validate my currency field with regex. I want to allow the following pattern entries
1.23
1
.45
0.56
56.00
No comma should be allowed. I've tried \d+(\.\d\d) but it allows only first, fourth and fifth entries. \d+(?:\.\d\d+)? allows all but third one.
Use \d* instead of \d+ before the decimal to match zero or more digits. Also add anchors (^ and $) or else it will pass as long as there is any match available. This would also validate an empty string, so if necessary you can use a lookahead to make sure there is at least one digit:
^(?=.*\d)\d*(?:\.\d\d)?$
Regexes for floating-point numbers are a solved problem:
\d*\.?\d+
For at least two decimals:
(\d*\.\d)?\d+
To make it more comprehensible:
\d+|\d*\.\d{2,}
And for exactly two decimals:
\d+|\d*\.\d{2}
Depending on your language, don't forget to anchor the expression so that it must match the whole string.
I want except some numbers in different syntax and I am trying to find the best Regex for this task/match.
First some valid numbers:
0.01
0.2
0.38
45
165.6
52732.08
999999999.99
And here some invalid numbers:
.01
.2
.50
.85
45.
45.0
45.00
00045.0
124.60
000124.60
124,6
000053853.01
999.999.999,99
999999999,99
After several tests I have created the following Regex:
^[1-9]?\d{1,9}\.?\d{1,2}(?<!0)$
But I always struggling on the number: 000058723.01
Any ideas? Thanks.
You can use this regex:
^(?!0+\d)\d+(?:\.(?![1-9]*0+$)\d{1,2})?$
Or:
^(?:0+|[1-9]\d*)(?:\.(?![1-9]*0+$)\d{1,2})?$
RegEx Demo
Try this pattern:
^((?:0|[1-9]+)(?:\.(?:\d+?[1-9]|[1-9]))?)$
Demo
You accept four kinds of input:
A number with no decimal places and without leading zeroes: [1-9]\d*
Zero followed by a dot followed by digits (without trailing zeroes): 0\.\d*[1-9]
A decimal number without leading or trailing zeroes: [1-9]\d*\.\d*[1-9]
Zero: 0
Putting the four together:
^([1-9]\d*|0\.\d*[1-9]|[1-9]\d*\.\d*[1-9]|0)$
Here is a fixed version of your regex:
^(?!0{2,})\d+(?:\.\d{1,2}(?<!0))?$
Here, initial 2 or more zeros are not allowed with the lookahead (?!0{2,}), and the decimal part is made optional within a non-capturing group (?:\.\d{1,2}(?<!0))?.
See demo
In case you do not want to match 0, you can exclude this in the negative lookahead:
^(?!0{2,}|0$)\d+(?:\.\d{1,2}(?<!0))?$
^^
See Demo 2
A number with optional decimals is composed from two pieces: the integer part and the optional decimal part that starts with a dot.
The integer part is either zero (0) or a sequence of digits that start with 1..9 (no 0) and can continue with zero or more digits:
0|[1-9][0-9]*
If you need to impose an upper limit on the integer part's length then replace * with {,n} where n is the maximum allowed length minus 1.
The decimal part starts with a dot (.) followed by zero or more digits and followed by one of 1..9 (no 0 allowed at the end).
The expression is:
\.[0-9]*[1-9]
Now let's combine them:
^(0|[1-9][0-9]*)(\.[0-9]*[1-9])?$
What I added when I joined the pieces:
^ - match the start of the string; without this the regex matches 45.0 from 00045.0;
parentheses around the integer part because of the lower precedence of |;
parentheses around the decimal part, followed by ? to signal the entire decimal part is optional;
$ - match the end of the string to avoid matching 124.6 from 124.60.
Remarks
The above regex was designed to match your examples. However, please notice that most programming languages allow most or all of the numbers you put in the "invalid" section and use a dot (.) as decimal separator. And many languages provide library functions that are able to parse the numbers that use a comma (,) as decimal separator.
Numbers without integer part (.85), without digits after the dot (45.) ore with trailing zeros (45.0) are valid and are interpreted without ambiguity.
The only troublemaker is the leading zero (00045.0). For integer numbers, most of the times it is a signal that the number is represented in base 8 while for real numbers it is simply ignored.
I need to figure out how to make my regex allow match correctly each time I type a number/decimal point. I want to limit the number of digits before and after the decimal point, which isnt too hard but i cant figure out how to allow the decimal point to match as well.
1 - match
12 - match
1234 - match
12345 - wrong
1234. - match
1234.1 - match
1234.12 - match
1234.123 - wrong
Other matched numbers
12.12
1.0
123.99
Edit:
So I want a max of 4 numbers before the decimal place and two after. Also the decimal place is optional.
The tricky part is that I want it to fail if the fifth character isn't a decimal point.
You need to specify your constraints better; I'm assuming you want a maximum of 4 before the dot and 2 after:
/^\d{1,4}(\.\d{0,2})?$/
edit: I added beginning and end of string matchers. Should work as you want now
You can use the following regex to select only those words that consists of digits and satisfying your condition.
/(?<=^|\s)\d{1,4}(?:\.\d{0,2})?(?=\s|$)/g
Positive lookahead and lookbehind are used to make sure that a whitespace is around the number.
DEMO
Debuggex Demo
Something like this will help
r'^\d{1,4}(\.\d{0,2})?$'
As you must be aware, \d represents a digit, . for the decimal point and {min_required,max_required}. Be sure to test your regular expression prior to using them here.
I believe I've found the "perfect" Regular Expression to check against for currency in jQuery Validate, except it seems to allow the user to put a single lone decimal at the end or a decimal with a single digit after.
Matches: 700. and 3.0
The Regex:
^\$?([1-9]{1}[0-9]{0,2}(\,[0-9]{3})*(\.[0-9]{0,2})?|[1-9]{1}[0-9]{0,}(\.[0-9]{0,2})?|0(\.[0-9]{0,2})?|(\.[0-9]{1,2})?)$
I've been playing with it in http://gskinner.com/RegExr/ but can't seem to modify it in the right places to fix my decimal issue.
Currently it matches everything I need it to:
700,000
700,000.00
700000
Here is the jQuery validator addMethod using #Kolink's regex for those of you curious:
jQuery.validator.addMethod("currency", function(value, element) {
return this.optional(element) || /^\$?(?=.)(?:[1-9]\d{0,2}(?:,?\d{3})*)?(?:\.\d{2})?$/.test(value);
}, "Please enter a valid number.");
In each case your regex is saying "blah blah blah, then optionally a decimal point followed by zero to two digits".
Try this instead:
^\$?(?=.)(?:[1-9]\d{0,2}(?:,?\d{3})*)?(?:\.\d{2})?$
It's a much simpler regex and it does everything your current one does... but better.
Breaking it down:
^ start of string
\$? optional dollar sign
(?=.) require at least one character (because your requirement is for the whole part to be optional, and the decimal to be optional, but requires at least one)
(?:[1-9]\d{0,2}(?:,?\d{3}))*)? optionally match an integer. This integer may or may not be thousand-separated. Must start with a non-zero digit.
(?:\.\d{2})? optionally match a dot followed by two digits.
$ end of string
I would do this:
^\$?(?=.)([1-9]\d{0,2}((,\d{3})*|\d*))?(0?\.\d\d)?$
See a live demo of this working with your examples.
I want users to be allowed to enter numbers, up to 3 digits before the decimal place, with an optional decimal place and a maximum of 2 digits after the optional decimal place.
I want it to match: 12, 123, 123.5, 123.55, 123.
I do not want it to match: abc, 1234, 123.555
What I have so far it:
^\d{0,3}(.?)\d{0,2}$
At the moment it is still matching 1234. I think I need to use the look behind operator somehow but I'm not sure how.
Thanks
Try this:
^\d{0,3}(?:\.\d{0,2})?$
Or better, to avoid just a .:
^(?:\d{1,3}(?:\.\d{0,2})?|\.\d{1,2})$
Specifically, note:
Escaping the dot, or it matches any character (except new lines), including more digits.
Made the whole decimal part optional, including the dot. That is - the decimal dot is not optional - it must be including if we are to match any digit from the decimal part.
Even if you have escaped the dot, ^\d{0,3}(\.?)\d{0,2}$ isn't correct. With the dot optional, it can match 12378: \d{0,3} matches 123, (\.?) doesn't match anything, and \d{0,2} matches 78.
Working example: http://rubular.com/r/OOw6Ucgdgq
What about this?
/^\d{0,2}(?:\d\.|\.\d|\d\.\d)?\d?$/
Maybe this (untested)
^(?=.*\d)\d{0,3}\.?(?<=\.)\d{0,2}$
Edit - the above is wrong.
#Kobi's answer is correct.
A lookahead could be added to his first version to insure a NOT just a dot or empty string.
^(?=.*\d)\d{0,3}(?:\.\d{0,2})?$
You have to put the combination of decimal point and the decimal numbers optional. In your regex, only the decimal number is optional. 1234 is accepted because 123 satisfy ^\d{0,3}, not existing decimal point satisfy (.?), and 4 satisfy \d{0,2}.
Kobi's answer provided you the corrected regex.