DecimalFormat

format decimal numbers with a specific pattern

Install

$ npm install decimal-format --save

or use pnpm

$ pnpm add decimal-format --save

Usage

import DecimalFormat from 'decimal-format';

const df = new DecimalFormat('#,##0.0#');
df.format(1234.995);  // 1,235.0
df.format(1234.956);  // 1,234.96

const df1 = new DecimalFormat('#,##0.0#%');
df1.format(0.34995); // 35.0%

const df2 = new DecimalFormat('#,##0.0#‰');
df2.format(0.034993); // 34.99‰

const df3 = new DecimalFormat('￥#,##0.00元');
df3.format(1234.995); // ￥1,235.00元

const df4 = new DecimalFormat('0.00E');
df4.format(1234); // 1.23E3

const df5 = new DecimalFormat('0.00E+');
df5.format(1234); // 1.23E+3

RoundingMode defines the rounding modes of the formatting

import DecimalFormat, { RoundingMode } from 'decimal-format';

const df = new DecimalFormat('#,##0.0#');
df.setRoundingMode(RoundingMode.UP);    // round away from zero
df.format(2.1)      // 3.0
df.format(-2.1)     // -3.0

df.setRoundingMode(RoundingMode.UNNECESSARY) // assert that no rounding is necessary
df.format(2.11)     // 2.11
df.format(2.123)    // throw exception

RoundingMode

| Enum | Description | | ----------- | ------------------------------------------------------------ | | UP | round away from zero | | DOWN | round towards zero | | CEILING | round towards positive infinity | | FLOOR | round towards negative infinity | | HALF_UP | round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up | | HALF_DOWN | round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down | | HALF_EVEN | round towards the "nearest neighbor" unless both neighbors are equidistant, in which case round toward the even neighbor | | UNNECESSARY | assert that the requested operation has an exact result, hence no rounding is necessary |