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在Javascript/Typescript中从数组中删除重复的子对象

key object arrays javascript

JilReg · 技术社区 · 5 年前

我有一个满是物体的阵列。几乎所有对象都有不同数量的键-值对。其中一些对象具有相同的键值对。

有没有一个很好的方法来删除所有的子对象副本?(子对象复制=和 全部的 可以在另一个对象中找到键值对。)

例如,在下面的示例中,它将删除所有中间对象,只保留第一个和最后一个对象。

非常感谢:)

我最接近的是从 here ,但我不知道如何添加if条件,以便只检查属性是否存在。

由多个属性(id和名称)唯一

arr.filter((v,i,a)=>a.findIndex(t=>(t.id === v.id && t.name===v.name))===i)

输入

input = [
  {
    "key0": {
      "key1": "value1",
      "key2": "value1",
      "key3": "value1",
      "key4": "value1",
      "key5": "value1"
    }
  },
  {
    "key0": {
      "key1": "value1",
      "key3": "value1",
      "key5": "value1"
    }
  },
  {
    "key0": {
      "key1": "value1",
      "key2": "value1",
      "key3": "value1"
    }
  },
  {
    "key0": {
      "key1": "value1",
      "key2": "value1",
      "key5": "value1"
    }
  },
  {
    "key0": {
      "key1": "value1",
      "key2": "value2",
      "key3": "value2",
      "key4": "value2",
      "key5": "value2",
      "key6": "value2"
    },
  {
    "key0": {
      "key1": "value2",
      "key2": "value2",
      "key3": "value2",
      "key4": "value2",
      "key5": "value2",
      "key6": "value2"
    }
  }
]

预期产量

output = [
  {
    "key0": {
      "key1": "value1",
      "key2": "value1",
      "key3": "value1",
      "key4": "value1",
      "key5": "value1"
    }
  },
  {
    "key0": {
      "key1": "value2",
      "key2": "value2",
      "key3": "value2",
      "key4": "value2",
      "key5": "value2",
      "key6": "value2",
    }
  }
]

1 回复 | 直到 5 年前

guillaumepotier 5 年前

这里有一个非常基本的O(n2)复杂溶液:

var input = [
  {
    "key0": {
      "key1": "value1",
      "key2": "value1",
      "key3": "value1",
      "key4": "value1",
      "key5": "value1"
    }
  },
  {
    "key0": {
      "key1": "value1",
      "key3": "value1",
      "key5": "value1"
    }
  },
  {
    "key0": {
      "key1": "value1",
      "key2": "value1",
      "key3": "value1"
    }
  },
  {
    "key0": {
      "key1": "value1",
      "key2": "value1",
      "key5": "value1"
    }
  },
  {
    "key0": {
      "key1": "value1",
      "key2": "value2",
      "key3": "value2",
      "key4": "value2",
      "key5": "value2",
      "key6": "value2"
    }
  },
  {
    "key0": {
      "key1": "value2",
      "key2": "value2",
      "key3": "value2",
      "key4": "value2",
      "key5": "value2",
      "key6": "value2"
    }
  }
];

var isIncluded = function (a, b) {
	for (var key in a) {
  	if (!b[key] || b[key] !== a[key])
    	return false;
  }
  
  return true;
};


var output = [];

for (var i = 0; i < input.length; i++) {
	var toInclude = true;

  for (var j = 0; j < input.length; j++) {
  	if (j === i)
    	continue;
      
    if (isIncluded(input[i].key0, input[j].key0)) {
    	toInclude = false;
      break;
    }
  }
  
  if (!toInclude)
  	continue;
    
  output.push(input[i]);
}

console.log(output);
// document.write(JSON.stringify(output));

请注意,由于您可能在其中一个对象中犯了错误(混合了value1和value2),因此输出得到3项

mplungjan Gvidas 5 年前

这里有一个解决方案,可以用elem处理每个数组 {key0:{}},... 你需要的格式。下面的eg处理的不仅仅是 value1 和 value2 :不管值多少!:)

let input = [ { "key0": { "key1": "value1", "key2": "value1", "key3": "value1", "key4": "value1", "key5": "value1" } }, { "key0": { "key1": "value1", "key3": "value1", "key5": "value1" } }, { "key0": { "key1": "value1", "key2": "value1", "key3": "value1" } }, { "key0": { "key1": "value1", "key2": "value1", "key5": "value1" } }, { "key0": { "key1": "value1", "key2": "value2", "key3": "value2", "key4": "value2", "key5": "value2", "key6": "value2" } }, { "key0": { "key1": "value2", "key2": "value2", "key3": "value2", "key4": "value2", "key5": "value2", "key6": "value2" } } ];

function format(input) {

  let output = input.map(el => Object.keys(el)).map(ell => ell[0]);

  //check if only 'key0' at root key
  let same = output.reduce((acc, curr) => acc == curr ? output[0] : false, output[0]) == output[0];
  if (!same) return;

  //list all possibles value (value1, value2, ...)
  let possibleVal = {};
  for (key in input) {
    for (sub in input[key]['key0']) {
      possibleVal[input[key]['key0'][sub]] = null;
    }
  }
  possibleVal = Object.keys(possibleVal); // make it an array

  // fill output with possible values as key and fill with all possible values
  output = {};
  possibleVal.map(el => output[el] = {});
  input.map(el => {
    Object.entries(el['key0']).map(ell => {
      let key = ell[0];
      let value = ell[1]
      output[value][key] = value;
    });
  });

  // format it correctly and return it
  return possibleVal.map(val => ({
    'key0': output[val]
  }));
}

let final = format(input);

console.log(JSON.stringify(final, null, 4));