Format JavaScript numbers to trim zeroes and have commas

Question

Here's what I need:

121 => 121
14231.439400000 => 14,231.4394
1.123456789 => 1.12345679
-9012.4430001 => -9,012.4430001

I've tried the following: return input.toFixed(8).toLocaleString().replace(/0*$/, '').replace(/\.$/, '');

and that doesn't add commas. I've also looked at numeraljs, but that doesn't have the decimal features I require (specifying up to 8 decimals out, or trimming)

Any help?

Answer 1

This should work on any browser that supports locales and the options described on MDN:

return input.toLocaleString("en", { 
    useGrouping: true, 
    maximumFractionDigits: 8 
});

Demonstration

And here's an alternative solution adapted from Elias Zamaria's answer here:

var x = input.toFixed(8).split('.');
return x[0].replace(/\B(?=(\d{3})+(?!\d))/, ',') + 
       ('.' + x[1]).replace(/\.?0+$/, '');

Demonstration

Answer 2

Or if you want to do it yourself:

function fixNumber(number){
    var roundedNumber = Math.round(parseFloat(number) * 100000000) / 100000000,
    	numberString = roundedNumber.toString(),
        parts = numberString.split('.'),
        integerPart = parts[0],
        decimalPart = parts.length > 1 ? parts[1] : '';

    integerPart = integerPart.split('').reverse().join('').replace(/(\d{3})/g, '$1,').split('').reverse().join('').replace(/^(-?),/, '$1');
    decimalPart = decimalPart.replace(/0+$/, '');
    
    return decimalPart.length ? integerPart + '.' + decimalPart : integerPart;
}

document.write(fixNumber(121) + '<br>');
document.write(fixNumber(14231.439400000) + '<br>');
document.write(fixNumber(1.123456789) + '<br>');
document.write(fixNumber(-9012.4430001) + '<br>');

JSFiddle

Answer 3

Internationalization Support is now readily available in all browsers and nodejs. The advantage to this is that it's fast and configurable. For example, you can specify a minimum number of decimal precision and a maximum.

// Decimal Style (1,234,56)
let formatter = new Intl.NumberFormat('en-US', { style: 'decimal', minimumFractionDigits: 0, maximumFractionDigits: 8 });
formatter.format(1234.5678); // result: "1,234.57"

// Currency Style ($1,234.56)
let formatter = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD', minimumFractionDigits: 0, maximumFractionDigits: 2 });
formatter.format(28761232.291); // result: "$28,761,232"