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regex replace value only keep numbers and limit decimal places to 2

I have the following text "2345dsds34.000" and i want the following value '234534.00'. I plan to do this via regex replace but somehow it doesnt limit the decimal places to 2.
I am using this "2345dsds34.000".replace(/[^\d+(\.\d{1,2})$]/g, '') but it keeps giving me 234534.000. How can i force it to limit it to 2 decimal points.
console.log("2345dsds34.000".replace(/[^\d+(\.\d{1,2})$]/g, ''))
Thanks

You can use toFixed JS Number function
Number( "2345dsds34.000".replace(/[^\d+(\.\d{1,2})$]/g, '') ).toFixed(2)

You can simply slice the last digit off with .slice(0, -1):
console.log("2345dsds34.000".replace(/[^\d+(\.\d{1,2})$]/g, '').slice(0, -1));

That regex is targetting the characters between some digits and some other digits having a decimal place.
Snapshot from https://regex101.com/
Then, the .replace() method is removing them. That all it does.
Since you don't know how many extra decimal you may have... I suggest you to use parseFloat() and .tofixed(2).
Please have a look at those two documentation links. ;)
var value = parseFloat("2345dsds34.000".replace(/[^\d+(\.\d{1,2})$]/g, '')).toFixed(2);
console.log(value);

You can simply use
[^\d.]
let str = "2345dsds34.000"
let op = parseFloat(str.replace(/[^\d.]+/g, '')).toFixed(2)
console.log(op)

By using a Regex with capturing parentheses It will look like this
var regex = /(\d{4})[a-z]+(\d{2})\.(\d{2}).*/;
var input_chain = "2345dsds34.000";
var output = input_chain.replace(regex, "$1$2.$3");
console.log(output);
Each capturing parentheses can be references in the second part of the replace method by their position number prefixed with a $

check whether csv form or not [duplicate]

What is the regular expression to validate a comma delimited list like this one:
12365, 45236, 458, 1, 99996332, ......

I suggest you to do in the following way:
(\d+)(,\s*\d+)*
which would work for a list containing 1 or more elements.

This regex extracts an element from a comma separated list, regardless of contents:
(.+?)(?:,|$)
If you just replace the comma with something else, it should work for any delimiter.

It depends a bit on your exact requirements. I'm assuming: all numbers, any length, numbers cannot have leading zeros nor contain commas or decimal points. individual numbers always separated by a comma then a space, and the last number does NOT have a comma and space after it. Any of these being wrong would simplify the solution.
([1-9][0-9]*,[ ])*[1-9][0-9]*
Here's how I built that mentally:
[0-9] any digit.
[1-9][0-9]* leading non-zero digit followed by any number of digits
[1-9][0-9]*, as above, followed by a comma
[1-9][0-9]*[ ] as above, followed by a space
([1-9][0-9]*[ ])* as above, repeated 0 or more times
([1-9][0-9]*[ ])*[1-9][0-9]* as above, with a final number that doesn't have a comma.

Match duplicate comma-delimited items:
(?<=,|^)([^,]*)(,\1)+(?=,|$)
Reference.
This regex can be used to split the values of a comma delimitted list. List elements may be quoted, unquoted or empty. Commas inside a pair of quotation marks are not matched.
,(?!(?<=(?:^|,)\s*"(?:[^"]|""|\\")*,)(?:[^"]|""|\\")*"\s*(?:,|$))
Reference.

/^\d+(?:, ?\d+)*$/

i used this for a list of items that had to be alphanumeric without underscores at the front of each item.
^(([0-9a-zA-Z][0-9a-zA-Z_]*)([,][0-9a-zA-Z][0-9a-zA-Z_]*)*)$

You might want to specify language just to be safe, but
(\d+, ?)+(\d+)?
ought to work

I had a slightly different requirement, to parse an encoded dictionary/hashtable with escaped commas, like this:
"1=This is something, 2=This is something,,with an escaped comma, 3=This is something else"
I think this is an elegant solution, with a trick that avoids a lot of regex complexity:
if (string.IsNullOrEmpty(encodedValues))
{
return null;
}
else
{
var retVal = new Dictionary<int, string>();
var reFields = new Regex(#"([0-9]+)\=(([A-Za-z0-9\s]|(,,))+),");
foreach (Match match in reFields.Matches(encodedValues + ","))
{
var id = match.Groups[1].Value;
var value = match.Groups[2].Value;
retVal[int.Parse(id)] = value.Replace(",,", ",");
}
return retVal;
}
I think it can be adapted to the original question with an expression like #"([0-9]+),\s?" and parse on Groups[0].
I hope it's helpful to somebody and thanks for the tips on getting it close to there, especially Asaph!

In JavaScript, use split to help out, and catch any negative digits as well:
'-1,2,-3'.match(/(-?\d+)(,\s*-?\d+)*/)[0].split(',');
// ["-1", "2", "-3"]
// may need trimming if digits are space-separated

The following will match any comma delimited word/digit/space combination
(((.)*,)*)(.)*

Why don't you work with groups:
^(\d+(, )?)+$

If you had a more complicated regex, i.e: for valid urls rather than just numbers. You could do the following where you loop through each element and test each of them individually against your regex:
const validRelativeUrlRegex = /^(^$|(?!.*(\W\W))\/[a-zA-Z0-9\/-]+[^\W_]$)/;
const relativeUrls = "/url1,/url-2,url3";
const startsWithComma = relativeUrls.startsWith(",");
const endsWithComma = relativeUrls.endsWith(",");
const areAllURLsValid = relativeUrls
.split(",")
.every(url => validRelativeUrlRegex.test(url));
const isValid = areAllURLsValid && !endsWithComma && !startsWithComma

How to remove string after fixed character

I have a string like this
str[0] = "99.1234567"
I wnat to remove all charcter after 3 decimal.
Means
str[0] = "99.123"
How to remove this after three decimal. Also sometime i will get only two decimal point like11.36 in that case i wnat to be ignored.

Just find the index of the period, and use substr to get the portion of the string you want.
str[0].substr(0, str[0].indexOf(".")+4);
it's OK if the string is shorter than the length specified in substr.

You can do this using Number.toFixed() , but first you need ot convert the string to number :
var str = "99.1234567"
console.log(Number(str).toFixed(3))

One way to do it :
parseFloat("99.1234567").toFixed(3) // "99.123"

If string :
str[0] = "99.1234567";
parseFloat(str[0]).toFixed(3);
console.log(str[0]); //"99.123"
Or
Math.round(str[0] * 1000)/1000;

print number with comma as hundred separator

I have a number like "7847258998" which I want to print with hundred comma separator in javascript.
The result should be:
7,84,72,58,998
i.e the first three digits from right should be grouped together. Remaining digits grouped in chunks of 2. I tried with following:
"7847258998".replace(/\B(?=(\d{3})+(\d{2})+(?!\d))/g, ",")
But it returns: 7,8,4,72,58998. What is the right expression?

Try this:
"7847258998".replace(/\B(?=(\d{2})*(\d{3})$)/g, ",");
I match the end of the string in the lookahead so that I'm always looking for something sane. Otherwise just about anything matches.
Tested on inputs length 1-10.. Enough to decide that it probably works. Pretty inefficient way to do it though, as for each character you have to parse the rest of the string.
But you did ask for a regular expression that does the job =)

function commafy(num)
{
num = num+"";
var re=/(-?\d+)(\d{3})/
while(re.test(num))
{
num=num.replace(re,"$1,$2")
}
return num;
}
function commafyback(num)
{
var x = num.split(',');
return parseFloat(x.join(""));
}
alert(commafy(7847258998))

You can convert the number to a locale string using the en-IN locale.
(7847258998).toLocaleString("en-IN")
If the value is a string, convert it to a number first:
const value = "7847258998"
Number(value).toLocaleString("en-IN")
Reference: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toLocaleString

Using Regular Expressions with Javascript replace method

Friends,
I'm new to both Javascript and Regular Expressions and hope you can help!
Within a Javascript function I need to check to see if a comma(,) appears 1 or more times. If it does then there should be one or more numbers either side of it.
e.g.
1,000.00 is ok
1,000,00 is ok
,000.00 is not ok
1,,000.00 is not ok
If these conditions are met I want the comma to be removed so 1,000.00 becomes 1000.00
What I have tried so is:
var x = '1,000.00';
var regex = new RegExp("[0-9]+,[0-9]+", "g");
var y = x.replace(regex,"");
alert(y);
When run the alert shows ".00" Which is not what I was expecting or want!
Thanks in advance for any help provided.
strong text
Edit
strong text
Thanks all for the input so far and the 3 answers given. Unfortunately I don't think I explained my question well enough.
What I am trying to achieve is:
If there is a comma in the text and there are one or more numbers either side of it then remove the comma but leave the rest of the string as is.
If there is a comma in the text and there is not at least one number either side of it then do nothing.
So using my examples from above:
1,000.00 becomes 1000.00
1,000,00 becomes 100000
,000.00 is left as ,000.00
1,,000.00 is left as 1,,000.00
Apologies for the confusion!

Your regex isn't going to be very flexible with higher orders than 1000 and it has a problem with inputs which don't have the comma. More problematically you're also matching and replacing the part of the data you're interested in!
Better to have a regex which matches the forms which are a problem and remove them.
The following matches (in order) commas at the beginning of the input, at the end of the input, preceded by a number of non digits, or followed by a number of non digits.
var y = x.replace(/^,|,$|[^0-9]+,|,[^0-9]+/g,'');
As an aside, all of this is much easier if you happen to be able to do lookbehind but almost every JS implementation doesn't.
Edit based on question update:
Ok, I won't attempt to understand why your rules are as they are, but the regex gets simpler to solve it:
var y = x.replace(/(\d),(\d)/g, '$1$2');

I would use something like the following:
^[0-9]{1,3}(,[0-9]{3})*(\.[0-9]+)$
[0-9]{1,3}: 1 to 3 digits
(,[0-9]{3})*: [Optional] More digit triplets seperated by a comma
(\.[0-9]+): [Optional] Dot + more digits
If this regex matches, you know that your number is valid. Just replace all commas with the empty string afterwards.

It seems to me you have three error conditions
",1000"
"1000,"
"1,,000"
If any one of these is true then you should reject the field, If they are all false then you can strip the commas in the normal way and move on. This can be a simple alternation:
^,|,,|,$

I would just remove anything except digits and the decimal separator ([^0-9.]) and send the output through parseFloat():
var y = parseFloat(x.replace(/[^0-9.]+/g, ""));

// invalid cases:
// - standalone comma at the beginning of the string
// - comma next to another comma
// - standalone comma at the end of the string
var i,
inputs = ['1,000.00', '1,000,00', ',000.00', '1,,000.00'],
invalid_cases = /(^,)|(,,)|(,$)/;
for (i = 0; i < inputs.length; i++) {
if (inputs[i].match(invalid_cases) === null) {
// wipe out everything but decimal and dot
inputs[i] = inputs[i].replace(/[^\d.]+/g, '');
}
}
console.log(inputs); // ["1000.00", "100000", ",000.00", "1,,000.00"]