javascript - 如何展平不同对象的嵌套数组但仅从现有属性名称获取值？

Question

我想知道如何展平不同对象的嵌套数组并仅从(任何对象的)现有属性名称中获取现有值？

我只想从 2 个不同对象的嵌套数组中获取所有 propertyId 值。

export interface LeftMenuItem {
    text: string;
    routerUrl?: string;
    isExpanded: boolean;  
    propertyId?: string;
    children: LeftMenuChildrenItem[];
}
export interface LeftMenuChildrenItem {
    text: string;
    routerUrl?. string;
    propertyId?: string;
    isCustomer: boolean
}

const leftMenuPropertyIds: string[] = [];

this.leftMenuItems.forEach(val1 => {
    if (val1.propertyId) {
        leftMenuPropertyIds.push(val1.propertyId);
    }
    if (val1.children.length > 0) {
        val1.children.forEach(val2 => {
            if (val2.propertyId) {
                leftMenuPropertyIds.push(val2.propertyId);
            }
        });
    }
});

console.log(leftMenuPropertyIds);

Answer 1

使用reduce方法压平数组和对象。减少将有助于删除不需要的节点。

const list = [
  {
    propertyId: "1",
    text: "1",
    children: [
      { propertyId: "2", text: "1", children: [] },
      { propertyId: "", text: "1", children: [] },
      { propertyId: "3", text: "1", children: [] }
    ]
  }
];

const flat = (v, arr) => {
  if (v.propertyId) arr.push(v.propertyId);
  (v.children || []).forEach(v2 => flat(v2, arr));
  return arr;
};
const rest = list.reduce((arr, item) => flat(item, arr), []);

console.log(rest);