Regex to validate number between two ranges - javascript

how to validate numbers between 0 to 99999.99 using regex?
basically it should accept the values like 0.01, 0000.01, .01 and 9999.99
also it should have only two values after dot(.)
I tried something like the below but it did not work for me.
/^[0-9]{1,5}.[0-9]{2}$/
decimal is optional
Could someone help pls.

The . character has special meaning in a regex, so you need to escape it.
Anyway, let me see if I got the rules straight:
Decimal point is optional
If decimal point not given:
Between 1 and 5 digits
If decimal point is present:
Between 0 and 5 digits before decimal point
Between 1 and 2 digits after decimal point
Since the number of digits depends on the presence of the decimal point, you make the regex have two choices, separated by |.
Choice 1 (no decimal point): [0-9]{1,5}
Choice 2 (decimal point): [0-9]{0,5}\.[0-9]{1,2}
Since you want anchors (^$), you can either put them in both choices, or surround the choice set with parenthesis. To make it non-capturing, use (?:xxx).
Final regex is one of these:
/^[0-9]{1,5}$|^[0-9]{0,5}\.[0-9]{1,2}$/
/^(?:[0-9]{1,5}|[0-9]{0,5}\.[0-9]{1,2})$/
You can see the second one in effect on regex101.

If javascript then below regex would work:
^\d{0,5}(((\.){0})|((\.){1}\d{1,2}))$
All the above mentioned cases are satisfying.

Thank you and ^(?:\d{1,5}(?:\.\d{1,2})?|\.\d{1,2})$ is what i was trying to get and this serves my purpose.

Javascript regex:
/^\d{1,5}(\.\d{1,2})?$/
Javascript demo

Related

How to use Regex to limit user input to numeric fields, with one allowed decimal and one allowed negative symbol in front

I am trying to only allow numeric values, along with a possible negative symbol at the front of the string, and a single decimal, using Regex in JavaScript. This input value will only allow for a possible 10 digits also.
Currently, when a user inputs text, I have this logic that will only allow numbers, negative signs, and decimals. However, I want to limit the number of the negative sign to one, and only allow this at the front of the string. Also, I want to limit the number of decimals to one.
input.slice(0, 10).replace(/[^0-9.\-]/, '');
Can anyone please help me figure this out?
You can do:
input.slice(0, 10).match(/([-]?)([0-9]+)([.]?)([0-9]?)/);
Short n sweet.
/^-?\d{0,10}(\.\d{0,3})?$/
optional negative char. at the start
allows max of 10 digits next
again optional decimal group with at most 3 decimal places
These barriers can be modified accordingly.

regex check for Float number -> not ending and stars with decimal point

I am facing issues with regex pattern for Float number -> that should not end or stars with decimal points..
I have tried following regex patter.. that is
regex = /^\d*\.?\d*$/
// on doing
regex.test(11.)
regex.test(.11)
// it is returning true in checking
// I need to make this as false, comment will be much helpful
thank you.
You should bear in mind that regex only works with strings. When you pass a non-string variable as input to a RegExp, it will first coerce it to a string type.
Have a look:
console.log(11. , 'and', .11); // => 11 and 0.11
So, the actual string values you pass to your ^\d*\.?\d*$ regex are 11 and 0.11 that can be matched with the given pattern. Actually, ^\d*\.?\d*$ is a regex that is usually used for a very loose live number input validation, e.g. see How to make proper Input validation with regex?.
What you want is to implement a final, on-submit validation pattern, so that it could not pass strings like 11. and .11. There have been lots of threads discussing this kind of regex:
Regular expression for floating point numbers
regular expression for finding decimal/float numbers?
Basically, for validation, you will need something like
/^\d+(?:\.\d+)?$/.test(input_string)
/^[0-9]+(?:\.[0-9]+)?$/.test(input_string)
/^[0-9]+(?:\.[0-9]{1,2})?$/.test(input_string) // Some need to only allow 1 or 2 fractional digits
/^[0-9]{1,3}(?:\.[0-9]{2})?$/.test(input_string) // 1-3 digits in the integer part and two required in the fractional part

Regex to allow negative values with maximum of 4 decimal places

I need a little help with changing the following regex to allow negative numbers. It needs to allow decimal numbers of up to a maximum of 4 decimal places, which it already does.
/^\d+(\.\d{1,4})?$/
Can anyone help?
Thanks
Just put -? before the first digit - "optionally match a minus sign"
Add the - in the character class with optional(?)
/^[-+]?\d+(\.\d{1,4})?$/
The following allows for integer numbers (123), integer with 1 to 4 fractional part (123.1234) and only 1 to 4 fractional part (.1234), that's usually accepted as a valid number. All options can be prefixed by plus or minus signs:
/^[-+]?(?:\d+|\d*(?:\.\d{1,4})?)$/
The (?:xxx) construction is preferred to (xxx) when we're not interested to capture the matches, because it requires less resources.

Regular expression that match decimal places

I have this code to test if a value entered in a INPUT is numeric:
$("#price").val().match(/^\d+$/);
I need some help rewriting this function to allow decimal places either with colon or dot meaning for example 230.00 is allowed and 230,00 is allowed too. Also the decimal places could be four or less. Any?
Regex: $("#price").val().match(/^\d+([,\.]\d{1,4})?$/);
Regex n2 with negative values: $("#price").val().match(/^-?\d+([,\.]\d{1,4})?$/);
If you need help parsing values related to some culture in specific, take a loot at this https://github.com/jquery/globalize. It's a library about globalization and localization.
Hope it helps!
$("#price").val().match(/^\d+((\.|,)\d+)?$/);
the above won't limit the number of decimal places to four, though.
By the way, that's a comma and not a "colon"
To match decimal places up to 4 only, use this
$("#price").val().match(/^\d+((\.|,)\d{1,4})?$/);
should match 1 to four numbers after . or ,

how to allow only floating point number to a text fiedl

How to allow only a valid floating point number into a text field
floating point like these only
15
15.41
7045.12
0.74
--only 2 places after the digit
--max one dot
--only positive number so no need for +/-
/^\d+(?:\.\d{1,2})?$/
and I bet this has been asked here before...
This regex allows integers or floats with one or two decimal places. The integer part is mandatory.
If your intent is not to validate input strings but to find decimal numbers inside a larger string, use this instead:
/\b\d+(?:\.\d{1,2})?\b/
Following should work
/\d+(\.\d{1,2})?/
This should work /([0-9]+(\.[0-9]{1,2})?)/ if you want to just match them.
If you want to validate a string - /^([0-9]+(\.[0-9]{1,2})?)$/

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