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How to create a Regular Expression with the following conditions

Numerical input should not exceed 8 digits ( counting numbers on both the side of the decimal). Example: 123456.78 or 0.12 or 1.23
Numerical values should be able to accept negative numbers. Example: -0.8 , or -1.23
Max of 2 decimal number allowed
Numerical value should not accept any alpahbets in the input box
I tried Creating the following regular expression but i am not able to figure it out quite efficiently
^-?[0-9]\d*(\.\d+)?[,8]$
Regular exp

To match the required number of digits and no more, lookahead at the beginning of the pattern for (?:\d\.?) 1 to 8 times, and then match \d*(?:\.\d{1,2})?$ to match a number which, if containing decimals, contains at maximum 2 decimal characters:
^-?(?=(?:\d\.?){1,8}$)\d*(?:\.\d{1,2})?$
https://regex101.com/r/rQMRVX/5
(unless you need to capture the decimal part, it can be a non-capturing group like above)

You can try this
^-?\d{1,8}.?\d{1,2}$
Link : https://regex101.com/r/x7yw5M/2

JavaScript regex to accept numbers with comma separator (thousands) and dot separator (decimals)

Could any of you help me with a regular expression which will accept these:
For every thousand a comma will be accepted.
No less than 4 decimal points in number
I've been testing this pattern but fails in some scenarios:
^\d+(\,\d+{1.3} \.d{1.4})*$
Valid inputs:
1
11
111
1,111
1,111,111
1.1111
11.1111
111.1111
1,111.1111
Invalid inputs:
Any letter
1,1
1.1
1.11
1,11.11
1,111.1
The main criterions are:
(4 decimal points are obligatory).
(3 numbers per thousand must have a comma.)

Is this more complicated than
/^\d\d?\d?(,\d\d\d)*(\.\d\d\d\d)?$/
or if you prefer
/^\d{1,3}(,\d{3})*(\.\d{4})?$/

Regex to validate number between two ranges

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

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 ,