array

用于flutter使用的数组拓展方法 (List extension function)

之后会拓展出更多的方法！

添加依赖

  dependencies:
    array: ^0.0.1

List.flat

  import 'package:array/array.dart';

  // 数组扁平化
  List list = [1, [2, [3, { 'name': [123] }]]];
  print(list.flat(1)); // [1, 2, [3, {name: [123]}]]
  print(list.flat()); // 默认是展开1层， [1, 2, [3, {name: [123]}]]

  // 如果你不知道数组的深度，你可以传入double.infinity：
  print(list.flat(double.infinity)); // [1, 2, 3, {name: [123]}]

List.flatMap

  import 'package:array/array.dart';

  // 数组扁平化
  // 它和flat不一样的是，它只会展开一层，而且接收一个方法，用于映射出对应的值
  List list = [{ 'name': 123, 'age': 0 }, { 'name': 124, 'age': 1 }];
  List res = list.flatMap((e) {
   print(e);
   return e['name'];
  });
  
  print(res);  // [123, 124]

List.filter

  import 'package:array/array.dart';

  // 数组过滤，和js一样
  List list = [{ 'name': 123, 'age': 0 }, { 'name': 124, 'age': 1 }];
  List res = list.filter((item, index, list) {
   return item['name'];
  });
  
  print(res);  // [{name: 123, age: 0}]

List.reducex

  import 'package:array/array.dart';

  List list = [{ 'name': 123, 'age': 0 }, { 'name': 124, 'age': 1 }];
  var res = list.reducex((returnValue, currentValue, index, sourceList) {
    returnValue.add({
      'currentKey': currentValue['name']
    });
    return returnValue;
  }, []);
  
  print(res);  // [{currentKey: 123}, {currentKey: 124}]

operator " - "

  import 'package:array/array.dart';

  List list1 = ['foo', 'bar', 'baz', 'qux'];
  List list2 = ['foo', 'qux'];
  
  print(list1 - list2);  // bar, baz

operator " + "

  import 'package:array/array.dart';

  List list = [0];
  List list1 = [{ 'name': 444, 'age': 0 }, { 'name': 124, 'age': 1 }];
  
  print(list + list1);  // [0, {name: 444, age: 0}, {name: 124, age: 1}]

operator " * "

  import 'package:array/array.dart';

  List list = List list = [1,null, 2, '12.3'];
  
  print(list * 3);  // [3.0, 0.0, 6.0, 36.900000000000006]