Replace a comma with a Dot using JavaScript

Replace a comma with a Dot using JavaScript #

Use the replaceAll() method to replace all commas with dots, e.g. str.replaceAll(',', '.'). The replaceAll method will return a new string where all commas are replaced with dots.

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const str1 = '123,456,789';

// ✅ Replace ALL Commas with Dots
const replaced1 = str1.replaceAll(',', '.');
console.log(replaced1); // 👉️ 123.456.789

// ✅ Replace FIRST comma with Dot
const replaced2 = str1.replace(/,/, '.');
console.log(replaced2); // 👉️ 123.456,789

// ✅ Replace ALL commas with Dot using Regex
const replaced3 = str1.replace(/,/g, '.');
console.log(replaced3); // 👉️ 123.456.789

The first example uses the String.replaceAll method to replace all commas in a string with dots.

The 2 arguments we passed to the replaceAll method are:

1. the substring we want to match in the string
2. the replacement for each match

The replaceAll method returns a new string where all of the matches are replaced by the provided replacement.

If you only need to replace the first occurrence of a comma with a dot, use the String.replace method.

Use the String.replace() method to replace the first occurrence of a comma with a dot, e.g. const replaced = str1.replace(/,/, '.');. The replace() method will return a new string where the first occurrence of a comma is replaced with a dot.

Copied!
const str1 = '123,456,789';

// ✅ Replace FIRST comma with Dot
const replaced2 = str1.replace(/,/, '.');
console.log(replaced2); // 👉️ 123.456,789

The first argument we passed to the replace method is a regular expression.

All we try to match in our regular expression is a single comma.

An alternative to using the replaceAll method is to use the replace method with the g (global) flag.

Use the replace() method to replace all commas with dots, e.g. const replaced = str1.replace(/,/g, '.');. The replace method will return a new string with all commas replaced by dots.

Copied!
const str1 = '123,456,789';

// ✅ Replace ALL commas with Dot using Regex
const replaced3 = str1.replace(/,/g, '.');
console.log(replaced3); // 👉️ 123.456.789

If you ever need help reading a regular expression, check out this regex cheatsheet from MDN.

Which approach you pick is a matter of personal preference. I'd go with the replaceAll() method to replace all occurrences of a comma with a dot, and the replace() method if I only need to replace the first occurrence.

Further Reading #

• Remove the Leading and Trailing Comma from a String in JS
• Replace all Commas in a String using JavaScript
• How to replace all Spaces in a String in JavaScript
• Parse a String with Commas to a Number in JavaScript
• Add Space after each Comma in a String using JavaScript
• Convert a Comma Separated String to Array in JavaScript