number-display

Display number smartly within a certain length.

const display = createDisplay({ length: 8 });

display(-254623933.876)    // result: -254.62M

The conversion follow this rules:

• result char length will never overflow length .
• replace null or wrong type inputs ( undefined / NaN / object ) to placeholder
• use locale string with commas ( 1,234,222 ) as possible ( configurable )
• trim number with units ( 1.23k ) when length is limited
• convert scientific notation ( 1.23e+4 ) to friendly form
• directly return input text if allowed ( configurable )
• when omitting decimals, you can change the rounding type, default to 'round'
• no decimal tailing zeros
• no float error

It also has a Dart version .

Install

yarn add number-display

Usage

We have built-in types, so Typescript is supported

We only export a createDisplay function for users to custom their display function. So the real display function has only one input: value . This separates the configuration and usage, which is more simple and clear.

import createDisplay from 'number-display';

const display = createDisplay({
  length: 8,
  decimal: 0,
});

<div>{display(data)}</div>

The complete configuration params are listed in the next section .

If the length overflow, the trimming rules in order are:

• omit the locale commas
• slice the decimal by the room left
• trim the integer with number units ( k, M, G, T, P )
• if the length is >= 5, any number can be trimmed within it. If it's less than 5 and input number is too long, display will throw an error.

Conversion examples:

createDisplay();

null => ''
NaN => ''
{} => ''

-123456789.123456789 => '-123.457M'
'123456' => '123,456'
-1.2345e+5 => '-123,450'

Note that usually we will try to convert the number-like string input value to real number , say '-123', but some special form will be regarded as text like 'NaN', '-1.2345e+5':

'-1.2345e+5' => '-1.2345e+'
'NaN' => 'NaN'

With some configs:

createDisplay({
  allowText: false,
  separator: false,
  placeholder: '--'
});

null => '--'
'abcdefghijklmn' => 'abcdefghi'
123456 => '123456'

Locale

By setting the seperator and decimalPoint , numbers can be any locale form: '4.623.933,8'.

Configurations

length

( default: 9 )

The max length the result would be. length should be longer then 5 so that any number can display ( say -123000 ) after trim, or you may get a console warning and length overflow.

decimal

( default: equals to length )

The max decimal length. Note that this is only a constraint. The final precision will be calculated by length, and less than this param. This param is the same as 'length' by default, witch means no additional limit. There will be no decimal trailing zeros.

placeholder

( default: '' )

The result when the input is neither string nor number, or the input is NaN, Infinity or -Infinity. It will be sliced if longer than length param.

allowText

( default: false )

Allow Text ( String that cant convert to number) as input and result. It will be sliced within length param. If false , result of text will be placeholder. Note that some special form will be regarded as text like 'NaN', '-1.2345e+5'.

separator

( default: ',' )

Set the locale string separators ( 1,234,222 ), if there are rooms. Set it to null if you don't need any. Only the first char is kept.

decimalPoint

( default: '.' )

Set the locale string decimal point. Only the first char is kept.

roundingType

( default: 'round' )

The rounding type when omitting decimals, enum in 'round', 'floor' or 'ceil'.

units

( default: ['k', 'M', 'G', 'T', 'P'] )

The digit units to use. Only the first char is kept for each unit. If the property is set to null or too short, it will fallback to the default.

Blogs

Displaying Numbers in Frontend