number_display #

Display number smartly within a certain length.

final display = createDisplay(length: 8);

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

To display data in a width-limited component, this function will smartly help you to convert number to a certain chart length. To be simple, plain, flexible and accurate, the conversion follow this rules:

• result chart length will never overflow length
• replace null, nan or infinity 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
• no decimal trailing zeros

Usage #

In version 2.* 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 'package:number_display/number_display.dart';

final display = createDisplay(
  length: 8,
  decimal: 0,
);

print(display(data));

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 exception.

Conversion examples:

createDisplay();

null => ''
double.nan => ''

-123456789.123456789 => '-123.456M'
'123456' => '123,456'
-1.2345e+5 => '-123,450'

With some configs:

createDisplay(
  comma: false,
  placeholder: '--'
);

null => '--'
123456 => '123456'

Configurations #

length

( default: 9 )

The max length the result would be. length should no less then 5 so that any number can display ( say -123000 ) after trim.

decimal

( default: 2 )

The max decimal length. Note that this is only a constraint. The final precision will be calculated by length, and less than this param. 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.

comma

( default: true )

Whether the locale string has commas ( 1,234,222 ), if there are rooms.