You can just replace every space and comma with space then trim those trailing spaces:
var str=" , this, is a ,,, test string , , to find regex,,in js. , ";
res = str.replace(/[, ]+/g, " ").trim();
jsfiddle demo
Answer from Jerry on Stack OverflowYou can just replace every space and comma with space then trim those trailing spaces:
var str=" , this, is a ,,, test string , , to find regex,,in js. , ";
res = str.replace(/[, ]+/g, " ").trim();
jsfiddle demo
you can use reg ex for this
/[,\s]+|[,\s]+/g
var str= "your string here";
//this will be new string after replace
str = str.replace(/[,\s]+|[,\s]+/g, 'your string here');
RegEx Explained and Demo
Removing commas in a string
javascript - Remove leading comma from a string - Stack Overflow
Remove commas from the string using JavaScript - Stack Overflow
[javascript] how to effectively convert string to array while removing commas and the space at the beginning/end if there was any?
What is the easiest way to remove commas from a string in JavaScript?
Can I remove commas from a number directly in JavaScript?
What is the difference between replace() and replaceAll() in JavaScript?
To remove the first character you would use:
var myOriginalString = ",'first string','more','even more'";
var myString = myOriginalString.substring(1);
I'm not sure this will be the result you're looking for though because you will still need to split it to create an array with it. Maybe something like:
var myString = myOriginalString.substring(1);
var myArray = myString.split(',');
Keep in mind, the ' character will be a part of each string in the split here.
In this specific case (there is always a single character at the start you want to remove) you'll want:
str.substring(1)
However, if you want to be able to detect if the comma is there and remove it if it is, then something like:
if (str[0] == ',') {
str = str.substring(1);
}
To remove the commas, you'll need to use replace on the string. To convert to a float so you can do the maths, you'll need parseFloat:
var total = parseFloat('100,000.00'.replace(/,/g, '')) +
parseFloat('500,000.00'.replace(/,/g, ''));
Related answer, but if you want to run clean up a user inputting values into a form, here's what you can do:
const numFormatter = new Intl.NumberFormat('en-US', {
style: "decimal",
maximumFractionDigits: 2
})
// Good Inputs
parseFloat(numFormatter.format('1234').replace(/,/g,"")) // 1234
parseFloat(numFormatter.format('123').replace(/,/g,"")) // 123
// 3rd decimal place rounds to nearest
parseFloat(numFormatter.format('1234.233').replace(/,/g,"")); // 1234.23
parseFloat(numFormatter.format('1234.239').replace(/,/g,"")); // 1234.24
// Bad Inputs
parseFloat(numFormatter.format('1234.233a').replace(/,/g,"")); // NaN
parseFloat(numFormatter.format('$1234.23').replace(/,/g,"")); // NaN
// Edge Cases
parseFloat(numFormatter.format(true).replace(/,/g,"")) // 1
parseFloat(numFormatter.format(false).replace(/,/g,"")) // 0
parseFloat(numFormatter.format(NaN).replace(/,/g,"")) // NaN
Use the international date local via format. This cleans up any bad inputs, if there is one it returns a string of NaN you can check for. There's no way currently of removing commas as part of the locale (as of 10/12/19), so you can use a regex command to remove commas using replace.
ParseFloat converts the this type definition from string to number
If you use React, this is what your calculate function could look like:
updateCalculationInput = (e) => {
let value;
value = numFormatter.format(e.target.value); // 123,456.78 - 3rd decimal rounds to nearest number as expected
if(value === 'NaN') return; // locale returns string of NaN if fail
value = value.replace(/,/g, ""); // remove commas
value = parseFloat(value); // now parse to float should always be clean input
// Do the actual math and setState calls here
}
i think this can be done by regEx by i don't how to look it up.
this is a learning project, but i am just thinking about the scale
i have a form where the user enter a bunch of categories and i want the user to separate those categories with a comma, but working on the case where the user add the comma but also a space after the comma (as we all do) or before the comma, how to go about treating this case, because i don't want to end up with two or three categories that are the same.
edit: i did it but i don't want to remove the post to help anyone with the same issue.
here's what i did
const categoriesAsString = e.target.value;
const categoriesTrimmed = categoriesAsString.trim();
const categoriesAsStringWithWhiteSpace = categoriesTrimmed.replace(/\s*,\s*/g,",");
const categoriesAsArray = categoriesAsStringWithWhiteSpace.split(",");
setCategories(categoriesAsArray);
This will remove the last comma and any whitespace after it:
str = str.replace(/,\s*$/, "");
It uses a regular expression:
The
/mark the beginning and end of the regular expressionThe
,matches the commaThe
\smeans whitespace characters (space, tab, etc) and the*means 0 or moreThe
$at the end signifies the end of the string
function removeLastComma(str) {
return str.replace(/,(\s+)?$/, '');
}
In your example you also want to trim the commas if there's spaces between them at the start or at the end, use something like this:
str.replace(/^[,\s]+|[,\s]+$/g, '').replace(/,[,\s]*,/g, ',');
Note the use of the 'g' modifier for global replace.
You need this:
s = s.replace(/[,\s]{2,}/,""); //Removes double or more commas / spaces
s = s.replace(/^,*/,""); //Removes all commas from the beginning
s = s.replace(/,*$/,""); //Removes all commas from the end
EDIT: Made all the changes - should work now.