javascript - 检查对象文字数组中的重复值并从中创建一个新对象

Question

我目前有任何对象文字数组，这些数组有可能会以重复值进入客户端(请参阅 Date 键)。

[
    {
        "Date": "2/26/2018",
        "Title": "Story 1"
    },
    {
        "Date": "2/27/2018",
        "Title": "Story 2"
    },
    {
        "Date": "2/27/2018",
        "Title": "Story 3"
    },
    {
        "Date": "2/28/2018",
        "Title": "Story 4"        
    }
]

如何检查前一个键的值以将其合并到 1 个新对象中，例如:

[
    {
        "Date": "2/26/2018",
        "Title": "Story 1"
    },
    {
        "Date": "2/27/2018",
        "Stories": {
            [
                {
                   "Title": "Story 2"
                },
                {
                   "Title": "Story 3"
                }
            ]
        }
    },
    {
        "Date": "2/28/2018",
        "Title": "Story 4"        
    }
]

问题在于 - 不能使用 Underscore.js 等框架。

想法？

Answer 1

您可以使用函数reduce

var array = [    {        "Date": "2/26/2018",        "Title": "Story 1"    },    {        "Date": "2/27/2018",        "Title": "Story 2"    },    {        "Date": "2/27/2018",        "Title": "Story 3"    },    {        "Date": "2/28/2018",        "Title": "Story 4"            }];

var result = Object.values(array.reduce((a, c) => {
  if (a[c.Date]) {
    a[c.Date].Stories.push({Title: c.Title});
  } else {
    a[c.Date] = { "Date": c.Date, "Stories": [{Title: c.Title}] };
  }
  
  return a;
}, {}));

console.log(result);

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