Parse a String with Commas to a Number in JavaScript

Parse a String with Commas to a Number #

To parse a string with commas to a number:

1. Use the replace() method to remove all the commas from the string.
2. The replace method will return a new string containing no commas.
3. Convert the string to a number.

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const str = '12,000,000.50';

const num = parseFloat(str.replace(/,/g, ''));

console.log(num); // 👉️ 123000000.5

We used the String.replace method to remove all of the commas from the string.

The forward slashes / / mark the beginning and end of the regular expression.

We only match a comma in the regular expression.

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const str = '12,000,000.50';

const num = parseFloat(str.replace(/,/g, ''));

console.log(num); // 👉️ 123000000.5

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

We want to remove all commas, so we replace each comma with an empty string.

The last step is to call the parseFloat function with the result.

The parseFloat function parses the provided string and returns a floating point number.

If the parseFloat function cannot convert the string to a number, because the string contains non-numeric characters, the method returns NaN (not a number).

Here are some examples of using the parseFloat function.

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console.log(parseFloat('100')); // 👉️ 100
console.log(parseFloat('100.5')); // 👉️ 100.5
console.log(parseFloat(10.5)); // 👉️ 10.5
console.log(parseFloat('a123')); //👉️ NaN

If you're looking to avoid using a regular expression, use the String.replaceAll method.

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const str = '12,000,000.50';

const num = parseFloat(str.replaceAll(',', ''));

console.log(num); // 👉️ 123000000.5

This code snippet achieves the same result. However, we passed a string instead of a regular expression to the replaceAll() method.

The second parameter is the replacement for each match.

Further Reading #

• How to Parse Float with 2 Decimal places in JavaScript
• Convert Comma Separated String to Numeric Array in JS
• Extract a Number from a String in JavaScript
• Check if String is a Valid Number in JavaScript
• Check if String contains at least one Number in JavaScript