InputFormatter should allow negative and decimal numbers - regex

I want to allow users to just adding numbers like
123456.78912445,
-12345.7777777899,
1234567,
-12345678.
There is no number limit.
How can i write Regrex pattern for this textformfield.
Same Question inputFormatter should allow just decimal numbers and negative numbers
TextFormField(inputFormatters:[FilteringTextInputFormatter.allow(RegExp())])

Try this: ^\-*\d+(?:.\d+)?$
And example: https://regex101.com/r/yQDyoM/1

Related

Regex to accept only numeric input with whole and half decimal point

I have used the below regex but it accept all values after decimal point. I want only whole numbers ( eg: 12) and half decimal point (eg 12.5)
Regex regex = new Regex("[^0-9.]+");
I want the below behavior.
For example
Valid numbers : 12, 12.5
Invalid numbers 12.1, 12.8
Try using this pattern:
\d+(?:\.5)?
This would match whole numbers, as well as numbers which half just a decimal component of 0.5. If you also want to allow for 0.0 decimal endings, then use:
\d+(?:\.[05])?
For your actual code, you may use:
Regex regex = new Regex("#\d+(?:\.5)?");

Regular expression to check if a string is number including decimal number

I want to check if a string is a number. The accepted range of numbers in my case varies a lot from large numbers with a lot of decimals like;
100000000000000000.000000000000000001
1
25.9897
Above values should be matched!
Values that should not match are;
10,000.4
e19
How can I approach this?
^\d+(\.\d+)?$
A number with any length \d+, then maybe some optional decimal part (\.\d+)?
Also important to utilize line anchors ^ and $ to filter cases like e19
A possible problem can be a value like; 010.5, leading 0s can be kinda problematic, is that acceptable? Otherwise the way to filter values with trailing 0s out is to use; ^[1-9]\d*(\.\d+)?$. Just FYI
see it on regex101

REGEX Parameters

I have a notepad with data that looks like this:
"$7.49"
"$124.00"
"$530.00"
How can I search through a range using regular expressions like 200-1000, but that values must be in "$XXX.XX" format.
Thanks for the help!
You can't easily manipulate numbers through regular expressions. It's doable though, so let's look at what you want to have.
Numbers are in the form \d+\.\d+, with no preceding zeroes.
You want to match numbers superior or equal to 200.
You want to match numbers lower or equal to 1000.
So, we have to look at our numbers like they are strings of characters. With the exception of 1000, all of those have three digits. So your regex is something like:
\$([2-9]\d\d\.\d\d|1000\.00)
That is, "a number with three digits left to the dot and the first one is 2 or higher or 1000.00".
This works with $XXX.XX \$\d+\.\d+. The problem with ranges are that numbers used in 3 digits bleed over to 4 digits and the regex gets way more complicated.
Use regex sets [ ] to limit the numbers/values.
So I would search for similar digits such as 200-999.xx which would be
\$[2-9]\d\d\.\d\d
or for four digits for 1000-1500
\$1[1-5]\d\d\.\d\d
If by range you mean number of digits, then go: \$\d{1,3}\,\d{1,2}

Regular expression for counting decimals

I need to validate a Textbox input which accepts decimal values. I require to count the number of digits entered after dot in the decimal number and restrict if the precision is more than 5.
Ex
Valid values
1.2
15.256
25.25486
Invalid
455.256485
^\d*(?:\.\d{1,5})?$
This should validate decimals with 5 after ..
^\d*(?:\.\d{1,5})$
Use this if it is striclty for decimals and not integers.

I need a single regex to check number comma and number

I need a regX which can match like 123,123 only. My regX is
var regX = /^\d*[0-9](|.\d*[0-9]|,\d*[0-9])*$/;
but its currently matching 123,123 and 123, as well
Valid case: 123,123 or 123,000 or 000,000
Invalid case: 123.123 or 123?123 or '123'.'123'
you should use this regex = \d+(,\d+)+
You might want to use the {x,y} quantifier. I matches at least X of the item, and at most Y. If you leave one out, it has no limit in that direction. If you just have one number, with no comma it matches exactly that amount.
Exactly three digits:
(\d{3}),(\d{3})
Three or more
(\d{3,}),(\d{3,})
Between 2 and 7 digits:
(\d{2,7}),(\d{2,7})
And so on...
It looks like you're actually trying to match a number with thousand separators.
Try this: /\d{1,3}(?:,\d{3})*/
If your numbers are positive integers you can use: \d+,\d+
If you want floating point numbers as well: (\d|.)+,(\d|.)+
although this will also match malformed numbers with multiple or misplaced decimal points including .,. etc.