Use Number.toLocaleString() method to format number with commas in JavaScript. This is a built-in method to transform a number value into a comma-separated string.
Example format number with commas in JavaScript
Simple example code pass “en-US” as the parameter so that it will always create a thousand separator for your number.
<!DOCTYPE html>
<body>
<script>
let n = 10200300;
let str = n.toLocaleString("en-US");
console.log(str);
</script>
</body>
</html>Output:
You can use the same method for floating numbers to format with commas.
<script>
let n = 10200300.5555;
let str = n.toLocaleString("en-US");
console.log(str);
</script>Output: 10,200,300.556
JS Format number with commas using regular expressions
Using regular expressions able to find and replace values in a given string and format it. For example, consider the following regex pattern:
/\B(?=(\d{3})+(?!\d))/gCode
Use the regex pattern in combination with the String replace() function to replace the markers with commas.
<script>
let n = numberWithCommas(234234.555);
num.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ',');
console.log(n); // "234,234.555"
</script>How to print a number with commas as thousands of separators in JavaScript?
Answer: Use RegEx with replace method.
function numberWithCommas(x) {
return x.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");
}Do comment if you have any doubts or suggestions on this JS formate program.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version