flutter pub add decimal基于插件公开信息、社区数据与项目使用情况整理的选型参考。
decimal 包在 Dart 中提供了精确的十进制算术，能够准确处理十进制数字，避免浮点运算中常见的精度损失。它支持精确的十进制表示和算术运算，非常适合用于财务计算以及其他需要高精度的场景。该包可在所有主要平台上兼容，包括移动设备、网页和桌面端。它提供了一个简洁的 API，用于创建、操作和格式化十进制数值，并完全控制舍入模式和精度。
以下为关联源码仓库的 README 原文快照，最新内容请访问源码仓库。
This project enable to make computations on decimal numbers without losing precision like double operations.
For instance :
// with double
print(0.2 + 0.1); // displays 0.30000000000000004
// with decimal
print(Decimal.parse('0.2') + Decimal.parse('0.1')); // displays 0.3
To use this library in your code :
pubspec.yaml :dependencies:
decimal:
dart code :import 'package:decimal/decimal.dart';
Decimal.parse('1.23').Hint : To make your code shorter you can define a shortcut for Decimal.parse :
final d = (String s) => Decimal.parse(s);
d('0.2') + d('0.1'); // => 0.3
You can use the intl package to format decimal
with DecimalFormat from the package:decimal/intl.dart library:
import 'package:decimal/decimal.dart';
import 'package:decimal/intl.dart';
main() {
var value = Decimal.parse('1234.56');
var formatter = DecimalFormatter(NumberFormat.decimalPattern('en-US'));
print(formatter.format(value));
}
Tip: you can define an extension to make it more fluent:
extension on Decimal {
String formatWith(NumberFormat formatter) => formatter.format(DecimalIntl(this));
}
main() {
var value = Decimal.parse('1234.56');
var formatter = DecimalFormatter(NumberFormat.decimalPattern('en-US'));
print(value.formatWith(formatter));
}
WARNING: For now (2024.05.30) intl doesn't work with NumberFormat.maximumFractionDigits greater than 15 on web plateform and 18 otherwise.
You can use the NumberFormat from intl package to parse formatted decimals
var currencyFormatter = DecimalFormatter(NumberFormat.simpleCurrency(name: 'USD'));
currencyFormatter.parse('\$3.14'); // => 3.14
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