在 javascript 中转换为 json,javascript,json,iteration"/>
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javascript - 转换多值 Map在 javascript 中转换为 json

问题描述

我有一个Map<String, List<Object>>，我想将其转换为JSON.

这是我所拥有的：
第 1 点：声明变量

var map = new Map(), //map
jsonObject= {}, // oject that needs to be converted to JSON
value1 = { topic: "someText1", status: "0", action: "1", comment: "someComment1" }, // values of Map
value2 = { topic: "someText2", status: "0", action: "0", comment: "someComment2" },
value3 = { topic: "someText3", status: "1", action: "1", comment: "someComment3" };

第 2 点：填充多值映射的函数

function populateMap(map, k, v) {
    map[k] = map[k] || [];
    map[k].push(v);
}

Point 3: populating Map
// map的key是web页面中各种属性的拼接，用|分隔

populateMap(map, 'release|attachment|license1', value1);
populateMap(map, 'release|attachment|license1', value2);
populateMap(map, 'release1|attachment1|license1', value1);
populateMap(map, 'release1|attachment1|license2', value2);
populateMap(map, 'release1|attachment1|license3', value3);
populateMap(map, 'release2|attachment2|license2', value1);
populateMap(map, 'release2|attachment2|license2', value2);

第 4 点：迭代 map 并填充 jsonObject

for (var i in map) {
    var keys = i.split('|'), // splitting keys based on |
    last = keys.pop(),
    values = map[i];
    values.forEach(function (item, index) {
        keys.reduce((r, a) => r[a] = r[a] || {}, jsonObject)[last] = item;
    });
}

Point 5：当前输出（控制台打印的jsonObject）

{
  "release": {
    "attachment": {
      "license1": "[Object]"
    }
  },
  "release1": {
    "attachment1": {
      "license1": "[Object]",
      "license2": "[Object]",
      "license3": "[Object]"
    }
  },
  "release2": {
    "attachment2": {
      "license2": "[Object]"
    }
  }
}

第6点：预期输出（jsonObject）

{
  "release": {
    "attachment": {
      "license1": "[Object, Object]" // expecting array of objects here ^^
    }
  },
  "release1": {
    "attachment1": {
      "license1": "[Object]",
      "license2": "[Object]",
      "license3": "[Object]"
    }
  },
  "release2": {
    "attachment2": {
      "license2": "[Object, Object]"
    }
  }
}

^^ 由于 map 有该键的对象数组，所以我想在jsonObject.

有人可以帮助我在第 4 点map的遍历中进行调整以获得预期的结果吗？

标签： javascriptjsoniteration

解决方案

您使用 、 、 和 等方法.set与.get;.has进行交互.delete。Map将其元素设置为属性是不正确的。

function populateMap(map, k, v) {
    let values = map.get(k);

    if (values === undefined) {
        map.set(k, values = []);
    }

    values.push(v);
}

然后遍历地图如下所示：

const jsonObject = {};

for (const [key, values] of map) {
    setPath(jsonObject, key.split('|'), values);
}

并且您的setPath实现几乎保持不变：

function setPath(obj, [...keys], item) {
    const last = keys.pop();
    keys.reduce((r, a) => r[a] = r[a] || {}, obj)[last] = item;
}

总而言之：

function populateMap(map, k, v) {
    let values = map.get(k);

    if (values === undefined) {
        map.set(k, values = []);
    }

    values.push(v);
}

function setPath(obj, [...keys], item) {
    const last = keys.pop();
    keys.reduce((r, a) => r[a] = r[a] || {}, obj)[last] = item;
}

const map = new Map();

populateMap(map, 'release|attachment|license1', 'value1');
populateMap(map, 'release|attachment|license1', 'value2');
populateMap(map, 'release1|attachment1|license1', 'value1');
populateMap(map, 'release1|attachment1|license2', 'value2');
populateMap(map, 'release1|attachment1|license3', 'value3');
populateMap(map, 'release2|attachment2|license2', 'value1');
populateMap(map, 'release2|attachment2|license2', 'value2');

const jsonObject = {};

for (const [key, values] of map) {
    setPath(jsonObject, key.split('|'), values);
}

console.log(JSON.stringify(jsonObject));

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