如何使用 map 函数重新组装以下 json？答案

【问题标题】：How can i reassemble the following json using map function?如何使用 map 函数重新组装以下 json？
【发布时间】：2019-05-26 06:08:54
【问题描述】：

我正在尝试从给定的 json 制作 json 格式

我在 nodejs 中使用 map 函数，但它不能正常工作。我在这里提供所有细节。我想要一个代码，它会给我所需的 json 格式。

给定 Json：

var x =
[
[
    {
        "title":"My feel about shape up",
        "answer":"neutral",
        "objectives":[
            "Awareness"
        ]
    },
    {
        "title":"How good is shape up ?",
        "answer":"a",
        "objectives":[
            "Awareness"
        ]
    }
],
[
    {
        "title":"My feel about shape up",
        "answer":"neutral",
        "objectives":[
            "Awareness"
        ]
    },
    {
        "title":"How good is shape up ?",
        "answer":"Awareness",
        "objectives":[
            "Awareness"
        ]
    }
]
];

我试过的代码：

result = x.map(function(subarray) {
var data  = subarray.map(v =>{
  const wd= {[v.title ]: v.answer}
   return wd;
   })
   return data;

})

实际输出：

[ [ { 'My feel about shape up': 'neutral' },
{ 'How good is shape up ?': 'a' } ],
[ { 'My feel about shape up': 'neutral' },
{ 'How good is shape up ?': 'Awareness' } ] ]

预期输出：

[ 
{ 'My feel about shape up': 'neutral',
'How good is shape up ?': 'a' } ,
{ 'My feel about shape up': 'neutral',
'How good is shape up ?': 'Awareness' } 
]

【问题讨论】：

标签： javascript arrays json object

【解决方案1】：

您从内部循环返回一个数组，而不是您需要创建一个对象来获得所需的结果，

let data = [[{"title":"My feel about shape up","answer":"neutral","objectives":["Awareness"]},{"title":"How good is shape up ?","answer":"a","objectives":["Awareness"]}],[{"title":"My feel about shape up","answer":"neutral","objectives":["Awareness"]},{"title":"How good is shape up ?","answer":"Awareness","objectives":["Awareness"]}]];

let final = data.map(value =>
  value.reduce((op, {title, answer}) => {
    op[title] = answer
    return op
  },{})
)
console.log(final)

【讨论】：

【解决方案2】：

您可以使用.map() 和.reduce() 方法来获得所需的输出：

const data = [[
    {"title":"My feel about shape up", "answer":"neutral", "objectives":[ "Awareness"]},
    {"title":"How good is shape up ?", "answer":"a", "objectives":[ "Awareness"]}
], [
    {"title":"My feel about shape up", "answer":"neutral", "objectives":["Awareness"]},
    {"title":"How good is shape up ?", "answer":"Awareness", "objectives":["Awareness"]}
]];

const result = data.map(
    arr => arr.reduce((r, {title: k, answer: v}) => (r[k] = v, r), {})
);

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

【讨论】：

【解决方案3】：

您应该为子数组使用reduce，以便为每个子数组获取一个对象；

var x = [[{"title":"My feel about shape up","answer":"neutral","objectives":["Awareness"]},{"title":"How good is shape up ?","answer":"a","objectives":["Awareness"]}],[{"title":"My feel about shape up","answer":"neutral","objectives":["Awareness"]},{"title":"How good is shape up ?","answer":"Awareness","objectives":["Awareness"]}]];
const res = x.map(e => e.reduce((acc, { title, answer }) => ({ ...acc, [title]: answer }), {}));
console.log(res);

ES5 语法：

var x = [[{"title":"My feel about shape up","answer":"neutral","objectives":["Awareness"]},{"title":"How good is shape up ?","answer":"a","objectives":["Awareness"]}],[{"title":"My feel about shape up","answer":"neutral","objectives":["Awareness"]},{"title":"How good is shape up ?","answer":"Awareness","objectives":["Awareness"]}]];
var res = x.map(function(e) {
  return e.reduce(function(acc, curr) {
    return Object.assign({}, acc, { [curr.title]: curr.answer });
  }, {});
});
console.log(res);

【讨论】：