javascript - 使用下划线从数组返回一个新数组

Question

我想返回一个只包含指定值的过滤数组

var messages: [{
     id: 1,
     name: "John",
     hashtag: ["#cool"]},

     {id: 2,
     name: "Bob",
     hashtag: ["#cool", "#sweet"]},

     {id: 3,
     name: "Bob",
     hashtag: ["#sweet"]} ];

// supposed to return the first two items in the array
var newArray = _.where(messages, {hashtag: "#cool"});

Answer 1

这里有一个纯函数式的方法，你可以用下划线来做，不过，对于这种事情，更喜欢 Ramda:

var messages = [{
    id: 1,
    name: "John",
    hashtag: ["#cool"]
  },

  {
    id: 2,
    name: "Bob",
    hashtag: ["#cool", "#sweet"]
  },

  {
    id: 3,
    name: "Bob",
    hashtag: ["#sweet"]
  }
]

var newArray = _.filter(messages, _.compose(_.partial(_.contains, _, '#cool'), _.property('hashtag')))

console.log(newArray)

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