使用 Underscore.js 基于 1 个字段合并 2 个对象 [英] Merge 2 objects based on 1 field using Underscore.js

问题描述

我有 2 个对象数组:

var a = [{ "image_id": 631293, "score": 73 },{ "image_id": 11848407, "score": 56 }];变量 b = [{image_id":631293，article_id":173}，{image_id":11848407，article_id":121 }];

我尝试应用如何将对象数组与下划线js合并a> 但不幸的是它根本不起作用.

由于 image_id，我需要合并两个对象数组.

所以我尝试了这个:

_.values(_.extendOwn(_.indexBy(a, 'image_id'),_.indexBy(b, 'image_id')))

但输出只是返回给我这个对象数组 a

我需要:

<预><代码>[{"image_id": 631293, "score": 73, "article_id": 173},{"image_id": 11848407, "score": 56, "article_id": 121}]

如何在不循环检查数组的每个元素并使用 findWhere 的情况下实现这一点?

解决方案

使用 indexBy 是一个好的开始.然后循环并扩展一个:

var indexed = _.indexBy(a, 'image_id');_.each(b, function(obj) {var master = indexed[obj.image_id];if (master) _.extend(master, obj);});

或者如果你想要一个新数组并让原始对象保持不变:

var 结果 = _.map(b, function(obj) {var master = indexed[obj.image_id];返回 _.extend({}, master, obj);});

var a = [{image_id":11848407，分数":56}, {image_id":631293，分数":73}, {"image_id": "虚拟",分数":1}];var b = [{"image_id": "测试",文章编号":0}, {image_id":631293，文章编号":173}, {image_id":11848407，文章编号":121}];var indexed = _.indexBy(a, 'image_id');_.each(b, function(obj) {var master = indexed[obj.image_id];if (master) _.extend(master, obj);});console.log(a);

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

I have 2 arrays of objects:

var a = [
    { "image_id": 631293, "score": 73 }, 
    { "image_id": 11848407, "score": 56 }
];

var b = [
    { "image_id": 631293, "article_id": 173 }, 
    { "image_id": 11848407, "article_id": 121 }
];

I have tried to apply method described in How can i merge array of objects with underscore js but unfortunately it does not work at all.

My need is to merge both arrays of objects thanks to image_id.

So I tried this :

_.values(
   _.extendOwn(
      _.indexBy(a, 'image_id'),
      _.indexBy(b, 'image_id')
   )
)

but output just return me this array of object a

I need to get :

[
    {"image_id": 631293, "score": 73, "article_id": 173}, 
    {"image_id": 11848407, "score": 56, "article_id": 121}
]

How can I achieve this without doing a loop to check every element of array and use a findWhere?

解决方案

Using indexBy is a good start. Then loop and extend one:

var indexed = _.indexBy(a, 'image_id');

_.each(b, function(obj) {
  var master = indexed[obj.image_id];
  if (master) _.extend(master, obj);
});

or if you want a new array and let the original objects untouched:

var result = _.map(b, function(obj) {
  var master = indexed[obj.image_id];
  return _.extend({}, master, obj);
});

var a = [{
  "image_id": 11848407,
  "score": 56
}, {
  "image_id": 631293,
  "score": 73
}, {
  "image_id": "dummy",
  "score": 1
}];

var b = [{
  "image_id": "test",
  "article_id": 0
}, {
  "image_id": 631293,
  "article_id": 173
}, {
  "image_id": 11848407,
  "article_id": 121
}];

var indexed = _.indexBy(a, 'image_id');

_.each(b, function(obj) {
  var master = indexed[obj.image_id];
  if (master) _.extend(master, obj);
});

console.log(a);

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

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