js-big-decimal

JS Big Decimal

Work with large numbers on the client side with high precision.

Installation

npm install --save js-big-decimal

Usage

Require in javascript as

var bigDecimal = require('js-big-decimal').bigDecimal;

For typescript, use

import { bigDecimal } from 'js-big-decimal';

Operations

bigDecimal(number)

Create a new objet of type BigDecimal. Supports parameters of type number and string. If string passed cannot be parsed as a number error is thrown. It is recommended to use string as it circumvents the issue of precision with JS native float implementation and max limit for integer.

It supports exponentiation, but only with integral exponent.

var n1 = new bigDecimal(12.6789);
var n2 = new bigDecimal("12345.6789");
var n3 = new bigDecimal('12.456e3'); // 12456

getValue()

Returns the string value of the decimal.

console.log(n2.getValue()); // "12345.6789"

getPrettyValue(number, digits, separator)

By default this returns the number in standard number format, comma after every three digts. Both arguments, digits - the number of digits (of the integral part) to group by, and separator - the character to mark the separation. Example of this can be to format a 16 digit number as credit card.

var value = bigDecimal.getPrettyValue("12345.6789"); // value = "12,345.6789"

Alternately, use the instance property. It returns the result as string.

var n3 = n2.getPrettyValue(); // n4 = "12,345.6789"

var num = new bigDecimal(1234567890123456)
var card = num.getPrettyValue(4, '-'); // cardNumber = "1234-5678-9012-3456"

round(number, precision)

Returns the rounded value to the specified precision (number of digits after decimal). The default is set to 0 if no argument is passed.

var value = bigDecimal.round("123.678", 2); // value = "123.68"

Alternately, use the instance property. It returns the result as bigDecimal.

var n3 = n1.round(2); // n3 = new bigDecimal("12.68")
var n4 = n2.round(); // n4 = new bigDecimal("12346")

compareTo(number1, number2)

Compare two numbers. Returns 1, 0 and -1 if number1 > number2, number1 == number2 and number1 < number2 respectively.

var value = bigDecimal.compareTo("23.678", "67.34"); // value = -1
var value = bigDecimal.compareTo("23.678", "23.6780"); // value = 0
var value = bigDecimal.compareTo("123.678", "67.34"); // value = 1

Alternately, use the instance property. It returns the result as Integer.

var n1 = new bigDecimal('1234');
var n2 = new bigDecimal('8765');
var value = n1.compareTo(n2); // value = -1

negate(number)

Returns negation of a given number.

var value = bigDecimal.negate("123.678"); // value = "-123.678";

Alternately, use the instance property. It returns the result as new bigDecimal.

var n = new bigDecimal('-1234');
var value = n.negate(); // value = new bigDecimal('1234')

add(augend, addend)

Add two numbers. Pass in negative for substraction. Ensure parameters are strings.

var sum = bigDecimal.add("23.678", "67.34"); // sum = "91.018"
var diff = bigDecimal.add("67.34", "-23.678"); // diff = "43.662"

Alternately, use the instance property. It returns the result as new bigDecimal.

var n1 = new bigDecimal('1234');
var n2 = new bigDecimal('8765');
var sum = n1.add(n2); // sum = new bigDecimal('9999')

subtract(minuend, subtrahend)

Subtract one number from another

var diff = bigDecimal.subtract("67.34", "23.678"); // diff = "43.662"

Alternately, use the instance property. It returns the result as new bigDecimal.

var n1 = new bigDecimal('12.67');
var n2 = new bigDecimal('130.7');
var diff = n1.subtract(n2); // diff = new bigDecimal('-118.03')

multiply(multiplicand, multiplier)

Multiply two numbers. Ensure parameters are strings.

var product = bigDecimal.multiply("-0.13", "0.00130"); // product = "-0.000169"

Alternately, use the instance property. It returns the result as new bigDecimal.

var n1 = new bigDecimal('-0.13');
var n2 = new bigDecimal('0.00130');
var product = n1.multiply(n2); // product = new bigDecimal('-0.000169')

divide(dividend, divisor, precision)

Divide two numbers. Pass arguments as string if calling on bigDecimal or pass an instance of bigDecimal if calling on object. precision is an optional parameter with default value of 8.

var quotient = bigDecimal.divide('45', '4', 2); // quotient = 11.25

Alternately, use the instance property. It returns the result as new bigDecimal.

var n1 = new bigDecimal('45');
var n2 = new bigDecimal('4');
var quotient = n1.divide(n2); // quotient = new bigDecimal('11.25')