Question

如何将以下JavaScript数组转换为由＆＃39; id＆＃39;键入的Immutable.Map？列表中的每个对象？

let buttons = [{ id: 'all', label: 'All', isSelected: false }, { id: '1', label: '1', isSelected: true }, { id: '2', label: '2', isSelected: false }, { id: '3', label: '3', isSelected: false }]

我希望能够做到：

map.get('all') // {id: 'all', label: 'All', isSelected: true}

Answer 1

这可以通过使用如下所示的不可变JS完成。

var buttons = [{
    id: 'all',
    label: 'All',
    isSelected: false
  }, {
    id: '1',
    label: '1',
    isSelected: true
  }, {
    id: '2',
    label: '2',
    isSelected: false
  }, {
    id: '3',
    label: '3',
    isSelected: false
}];

buttonImmutableList = Immutable.fromJS(buttons)
buttonImmutableMap = buttonImmutableList.reduce((a,c)=>  a.set(c.get('id'),c), Immutable.Map())

Answer 2

使用不可变：

var buttons = [{
    id: 'all',
    label: 'All',
    isSelected: false
  }, {
    id: '1',
    label: '1',
    isSelected: true
  }, {
    id: '2',
    label: '2',
    isSelected: false
  }, {
    id: '3',
    label: '3',
    isSelected: false
}];

var array = {};

for(var index in buttons) {
    var token = buttons[index];
    array[token.id] = token;
}

var map = new Immutable.Map(array);

var test = map.get('all');

window.alert(test.label);

如果您想添加密钥 - ＆gt;稍后，将修改映射，从而使当前实例无效。为此，您需要将变量map重新分配给最新的返回有效实例：

map = map.set(key, value);

通过自定义键将Seq转换为Map

2 个答案: