Imagine you have a website that has numerous forms such as an online shopping website, an internal tool for a specific customer to store a lot of data, a forum, a customer complaint website, online tests, etc. In such a website you probably took care of all the data validation from the forms and do not allow malformed or malicious data. But one of the most important thing that remains is that number formatting. There are various formats for numbers to be stored in the database. There can be currencies, computer bytes, test scores, percentages, etc. Instead of writing different functions to convert each of the numbers to that particular format, there is a JavaScript library out available open source which is called as Numeral.js. Number formatting has never been so easy. It's as easy as you go on the numeral.js website, look up for the format you want and just put it in the syntax, the library will take the input number in literally any format and convert it into the output format required. The most important things that I really love about this library is that the function takes literally any input and formats the data i.e. to convert the data to normal numeric format (23), it can take the inputs such as but not limited to 23rd, 23.00, $23, etc. You can play around with a lot of formats available to include currency symbols such as dollar in the beginning or the end, convert to certain decimal places, add commas, etc. It does not only account for the numbers for also formats for computer bytes, percentages, time and exponential.

NumearlJs is opensource free for commercial use library that simply delivers what you expect, has 0 dependencies and learning curve around 20min, simply install and use out of the box. Great support of internationalisation..