javascript - 递归地过滤数组寻找 parent

Question

我有一个这样的数组:

[
    {"id":"one","name":"school", "selected": false, "children":[
      {"id":"1","name":"school", "selected": false},
      {"id":"2","name":"student", "selected": true},
      {"id":"3","name":"teacher", "selected": false}
      ]},
      {"name":"two","name":"school", "selected": false, "children":[
      {"id":"1","name":"school", "selected": true},
      {"id":"3","name":"teacher", "selected": false}
      ]},
      {"name":"three","name":"school", "selected": true, "children":[
      {"id":"1","name":"school", "selected": false},
      {"id":"2","name":"student", "selected": false}
      ]}
  ]

我如何过滤该数组以仅获取字段选择为 true 的对象的名称？

输出应该是对象名称的数组:

[student, school, school]

我用 lodash 试过了:

_.filter(array, {selected: true}).map(function (division) {
            return array.name;
        });

但这总是返回根对象，而不是子对象中的对象。

Answer 1

您可以迭代并查看所需属性 selected 是否为 true，推送到结果，如果有子项，则迭代子项。

这适用于 Array#forEach

var data = [{ "id": "one", "name": "school", "selected": false, "children": [{ "id": "1", "name": "school", "selected": false }, { "id": "2", "name": "student", "selected": true }, { "id": "3", "name": "teacher", "selected": false }] }, { "name": "two", "name": "school", "selected": false, "children": [{ "id": "1", "name": "school", "selected": true }, { "id": "3", "name": "teacher", "selected": false }] }, { "name": "three", "name": "school", "selected": true, "children": [{ "id": "1", "name": "school", "selected": false }, { "id": "2", "name": "student", "selected": false }] }],
    result = [];

data.forEach(function iter(o) {
    o.selected && result.push(o.name);
    (o.children || []).forEach(iter);
});
  
console.log(result);

与lodash相同_.forEach

var data = [{ "id": "one", "name": "school", "selected": false, "children": [{ "id": "1", "name": "school", "selected": false }, { "id": "2", "name": "student", "selected": true }, { "id": "3", "name": "teacher", "selected": false }] }, { "name": "two", "name": "school", "selected": false, "children": [{ "id": "1", "name": "school", "selected": true }, { "id": "3", "name": "teacher", "selected": false }] }, { "name": "three", "name": "school", "selected": true, "children": [{ "id": "1", "name": "school", "selected": false }, { "id": "2", "name": "student", "selected": false }] }],
    result = [];

_.forEach(data, function iter(o) {
    o.selected && result.push(o.name);
    _.forEach(o.children, iter);
});
  
console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.15.0/lodash.min.js"></script>

带有 Array#reduce 的版本.

var data = [{ "id": "one", "name": "school", "selected": false, "children": [{ "id": "1", "name": "school", "selected": false }, { "id": "2", "name": "student", "selected": true }, { "id": "3", "name": "teacher", "selected": false }] }, { "name": "two", "name": "school", "selected": false, "children": [{ "id": "1", "name": "school", "selected": true }, { "id": "3", "name": "teacher", "selected": false }] }, { "name": "three", "name": "school", "selected": true, "children": [{ "id": "1", "name": "school", "selected": false }, { "id": "2", "name": "student", "selected": false }] }],
    result = data.reduce(function iter(r, o) {
        o.selected && r.push(o.name);
        return (o.children || []).reduce(iter, r);
    }, []);
  
console.log(result);

还有另一个带有 lodash 的版本 _.reduce .

var data = [{ "id": "one", "name": "school", "selected": false, "children": [{ "id": "1", "name": "school", "selected": false }, { "id": "2", "name": "student", "selected": true }, { "id": "3", "name": "teacher", "selected": false }] }, { "name": "two", "name": "school", "selected": false, "children": [{ "id": "1", "name": "school", "selected": true }, { "id": "3", "name": "teacher", "selected": false }] }, { "name": "three", "name": "school", "selected": true, "children": [{ "id": "1", "name": "school", "selected": false }, { "id": "2", "name": "student", "selected": false }] }],
    result = _.reduce(data, function iter(r, o) {
        o.selected && r.push(o.name);
        return _.reduce(o.children, iter, r);
    }, []);
  
console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.15.0/lodash.min.js"></script>