Question

我对来自lodash源代码的测试输出感到困惑：

我的任务是获取包含多个对象的地图的键。出于某种原因，我需要遍历地图并获取对象。以下是我的源代码：

var results = {"1":[1,2,3],"2":[2,4,6]};
var out = _.map(results, (result) => {
  //console.log(result);
  let key = _.keys(result);//I expect the key to be 1 or 2
  //... doing something else with the value, I assume is [1,2,3] or [2,4,6]
});
console.log(out);

我希望我的result为{'1': [ 1, 2, 3 ]}或{'2': [ 2, 4, 6 ]}，以便在我的迭代中获得1或2的密钥。但我得到的是result是[1,2,3]或[2,4,6]，我得到的密钥是[ undefined , undefined]。

我对结果感到很困惑。有人可以解释吗？谢谢！

Answer 1

使用var results = {"1":[1,2,3],"2":[2,4,6]}; var out = _.keys(results, (result) => { console.log(result); //... doing something else }); console.log(out);

＆＃13;

<script src="https://cdn.jsdelivr.net/lodash/4.13.1/lodash.min.js"></script>

＆＃13;

var contacts = ['Billy Bob', 'John', 'Bill', 'Sarah'];

var filters = ['Bill', 'Sarah'];

contacts = _.filter(contacts, function(contact) {
    return _.every(filters, function(filter) { return (contact.indexOf(filter) === -1); });
});

// ['John']

＆＃13;

Answer 2

我想我不应该从一开始就使用地图，因为它返回

更理想的方式是：

var results = {"1":[1,2,3],"2":[2,4,6]};
var out = _.each(results, (value, key) => {
  console.log(key);
  //Do something else with the value and get some `data`, which depends on both key and value
  return data;
});

lodash：迭代每个对象并获取其密钥

2 个答案: