如何删除包含相同“名称”的重复“地点”名称？答案

【问题标题】：How to remove the repeating `place` name which contains the same `name`?如何删除包含相同“名称”的重复“地点”名称？
【发布时间】：2023-03-09 07:50:01
【问题描述】：

我发现以下answer 对删除包含重复项的重复对象数组有很大帮助。

我已经为我修改的示例制作了fork。

相关功能：

const uniqueArray = things.thing.filter((thing,index) => {
  return index === things.thing.findIndex(obj => {
    return JSON.stringify(obj) === JSON.stringify(thing);
  });
});

例如我有：

[
  {"place":"here","name":"stuff"},
  {"place":"there","name":"morestuff"},
  {"place":"there","name":"morestuff"},
  {"place":"herehere","name":"stuff"}
]

它会返回：

[
  {"place":"here","name":"stuff"},
  {"place":"there","name":"morestuff"},
  {"place":"herehere","name":"stuff"}
]

如何删除包含相同name 的重复place 名称？

预期输出：

[
  {"place":"here","name":"stuff"},
  {"place":"there","name":"morestuff"}
]

【问题讨论】：

您可能希望使用 Array.reduce 代替，其中累加器是“过滤”对象，只有当累加器不包含所需项目时才会推送下一个项目。 const uniqueArray = things.thing.reduce((acc, next) => { if (acc.find(i => i.place === next.place)) return acc; else return (acc.push(next), acc); }, []);
对不起，我忘了放预期的输出。

标签： javascript arrays object duplicates

【解决方案1】：

您可以reduce 覆盖对象数组。简单来说，如果累加器中已经存在键值与当前对象相同的对象，就不要再添加了。

这里有一个函数可以让您指定要删除的密钥：

const arr = [
  {"place":"here","name":"stuff"},
  {"place":"there","name":"morestuff"},
  {"place":"there","name":"morestuff"},
  {"place":"herehere","name":"stuff"}
];

// Accepts an array and a key that should have the
// duplicates removed
function remove(arr, key) {

  // Iterate over the array passing in the accumulator
  // and the current element
  return arr.reduce((acc, c) => {

    // If there is an object in the accumulator with the
    // same key value as the current element simply return the
    // accumulator
    if (acc.find(obj => obj[key] === c[key])) return acc;

    // Otherwise add the current element to the accumulator
    // and return it
    return acc.concat(c);
  }, []);
}

function showJSON(arr, id) {
  const json = JSON.stringify(arr, null, 2);
  document.querySelector(`#${id} code`).textContent = json;
}

// remove duplicate places
showJSON(remove(arr, 'place'), 'places');

// remove duplicate names
showJSON(remove(arr, 'name'), 'names');

<div id="places">
Removed duplicate places
<pre><code></code></pre>
</div>

<div id="names">
Removed duplicate names
<pre><code></code></pre>
</div>

【讨论】：

【解决方案2】：

检查一下

  const things = [
        {"place":"here","name":"stuff"},
        {"place":"there","name":"morestuff"},
        {"place":"there","name":"morestuff"},
        {"place":"herehere","name":"stuff"}
    ]

    const uniqueArray = things.reduce((accumulator, currentValue) => {
        if (accumulator.find(a => a.name === currentValue.name))
            return accumulator;
        else
            return (accumulator.push(currentValue), accumulator);
    }, []);

输出

    [ { place: 'here', name: 'stuff' },
      { place: 'there', name: 'morestuff' } ]

【讨论】：

developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/… 看看这个你就能明白它是如何工作的

【解决方案3】：

您可以将数组归约与过滤器一起使用

let data=[
  {"place":"here","name":"stuff"},
  {"place":"there","name":"morestuff"},
  {"place":"there","name":"morestuff"},
  {"place":"herehere","name":"stuff"}
]

// Using reduce() to separate the contents we want
let result=data.reduce((acc,value)=>{
  if(acc.filter(val=>val.name==value.name).length==0) // checking the accumulator if it already containsa the value
  {
    acc.push(value); // if the array returned is of length==0 we can push in it
  }
return acc;

},[])
console.log(result);

见Array Filter，Array.prototype.Reduce

【讨论】：