javascript - 提取内部数组和对象数组

Question

var objs = [
  {labels: ["label1", "label2"]}, 
  {labels: ["label1", "label3"]},
  {labels: ["label2", "label4"]} 
]

我正在尝试提取此[“label1”，“label2”，“label3”，“label4”]

labels = this.get('objs').map(function(obj) {
           return obj.labels.map(function(label) {
             return label;
           });
         });
console.log(labels);

但是上面的代码打印了 [["label1", "label2"], ["label1", "label3"], ["label2", "label4"]]

有人可以帮我解决这个问题吗？

Answer 1

首先，您可以映射 objs 数组以仅获取 labels 数组，然后使用 Set 删除重复条目。

const objs = [
  {labels: ["label1", "label2"]}, 
  {labels: ["label1", "label3"]},
  {labels: ["label2", "label4"]},
];

const r = [...new Set([].concat(...objs.map(({ labels }) => labels)))];

console.log(r);

ES5:

const objs = [
  {labels: ["label1", "label2"]}, 
  {labels: ["label1", "label3"]},
  {labels: ["label2", "label4"]},
];

const r = [...new Set([].concat(...objs.map(function(v) {
  return v.labels;
})))];

console.log(r);