基于并集和交集合并两个json数组对象 [英] Merging two json array object based on union and intersection

问题描述

我正在尝试将两个json数组与对象作为元素合并.对于这两个json，您都可以参考 plunkr文件.我已经成功检索了预期的最终结果数组id，但是我不知道如何如下所示形成预期的json.我为此使用下划线js.

I am trying to merge two json array with objects as element. You may refer to this plunkr file for both json. I have succesfully retrieve the expected final outcome array id, but I do not know how to form back the expected json as below. I am using underscore js for this purpose.

注意:如果对象存在于newJson中，而在currentJson中不存在，则合并后，默认情况下它将处于 inactive 状态.

Note: If object exist in newJson and not in currentJson, after merge, it will be inactive state by default.

我不确定我是否使用了正确的方法.这是我尝试过的:

I am not sure whether I am using the correct approach. This is what I have try:

var newJsonID = _.pluck(newJson, 'id');
var currentJsonID =  _.pluck(currentJson, 'id');
var union = _.union(newJsonID, currentJsonID);
var intersection = _.intersection(currentJsonID, newJsonID);
var final = _.difference(union, _.difference( currentJsonID, intersection);

预期的最终结果:

   [
    {
        "id": "12",
        "property1Name": "1"
        "status": "inactive"
    },
    {
        "id": "11",
        "property1Name": "1"
        "status": "inactive"
    },
    {
        "id": "10",
        "property1Name": "1"
        "status": "inactive"
    },
    {
        "id": "9",
        "property1Name": "1"
        "status": "active"
    }
]

推荐答案

使用纯Javascript的解决方案，具有两个循环和一个用于查找的哈希表.

A solution in plain Javascript with two loops and a hash table for lookup.

function update(newArray, currentArray) {
    var hash = Object.create(null);
    currentArray.forEach(function (a) {
        hash[a.id] = a.status;
    });
    newArray.forEach(function (a) {
        a.status = hash[a.id] || 'inactive';
    });
}

var newJson = [{ "id": "12", "property1Name": "1" }, { "id": "11", "property1Name": "1" }, { "id": "10", "property1Name": "1" }, { "id": "9", "property1Name": "1" }],
    currentJson = [{ "id": "10", "property1Name": "1", "status": "inactive" }, { "id": "9", "property1Name": "1", "status": "active" }, { "id": "8", "property1Name": "1", "status": "active" }, { "id": "7", "property1Name": "1", "status": "inactive" }];
   
update(newJson, currentJson);
document.write('<pre>' + JSON.stringify(newJson, 0, 4) + '</pre>');

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