我想以有效的方式修改列表中特定元素的值

Question

如何让功能更高效？

这是我写的所有测试代码：

// ignore_for_file: public_member_api_docs, sort_constructors_first
import 'package:flutter_test/flutter_test.dart';

void main() {
  test(
    'find list item and apply math',
    () {
      final mockList = <Model>[
        Model(id: '1', name: 'Cortado', price: 12),
        Model(id: '2', name: 'Caffe Latte', price: 24),
        Model(id: '3', name: 'Americano', price: 48),
        Model(id: '4', name: 'Turkish Coffee', price: 96),
        Model(id: '5', name: 'Filter Coffee', price: 64),
        Model(id: '6', name: 'Flat White', price: 128),
      ];

      final selectItems = [mockList[0], mockList[3]];
      final result = findAndOperate(
        mainList: mockList,
        selectedList: selectItems,
        operations: Operations.PLUS,
        value: 40,
      );
      print(result);
    },
  );
}

List<Model> findAndOperate({
  required double value,
  required Operations operations,
  required List<Model> mainList,
  required List<Model> selectedList,
}) {
  for (final selectItem in selectedList) {
    for (final item in mainList) {
      if (item == selectItem) {
        final itemIndex = mainList.indexOf(item);
        switch (operations) {
          case Operations.PLUS:
            final changeItem =
                selectItem.copyWith(price: selectItem.price + value);
            mainList.removeAt(itemIndex);
            mainList.insert(itemIndex, changeItem);
          case Operations.MULTIPLICATION:
            final changeItem = selectItem.copyWith(
              price: selectItem.price + (selectItem.price * value),
            );
            mainList.removeAt(itemIndex);
            mainList.insert(itemIndex, changeItem);
        }
      }
    }
  }
  return mainList;
}

// ignore: constant_identifier_names
enum Operations { PLUS, MULTIPLICATION }

// ignore: one_member_abstracts

class Model {
  Model({required this.id, required this.name, required this.price});

  final String id;
  final String name;
  final double price;

  Model copyWith({
    String? id,
    String? name,
    double? price,
  }) {
    return Model(
      id: id ?? this.id,
      name: name ?? this.name,
      price: price ?? this.price,
    );
  }

  @override
  String toString() => 'MockModel(id: $id, name: $name, price: $price)';

  @override
  bool operator ==(covariant Model other) {
    if (identical(this, other)) return true;

    return other.id == id && other.name == name && other.price == price;
  }

  @override
  int get hashCode => id.hashCode ^ name.hashCode ^ price.hashCode;
}

我编写的函数按预期工作，但我对此很陌生，我很好奇我可以改进或学习什么。

运行该函数时出现的结果：

[MockModel(id: 1，名称：Cortado，价格：52.0)，MockModel(id：2，名称：Caffe Latte，价格：24.0)，MockModel(id：3，名称：Americano，价格：48.0)，MockModel( id: 4, 名称: 土耳其咖啡, 价格: 136.0), MockModel(id: 5, 名称: 过滤咖啡, 价格: 64.0), MockModel(id:6,名称:Flat White,价格:128.0)]

Answer 1

1. 开关盒中缺少

   break;

   语句。这意味着代码将继续到下一个案例，但这实际上是不需要的。

2. 我很确定你可以避免内循环。您正在检查

   mainList

   中的每个项目和

   selectedList

   中的每个项目