如何使用 javascript 或 lodash 从对象数组中删除不匹配的对象

Question

我正在从服务器获取两个对象数组，如下所示：

var duplicateTestData = [
    { 
        licenseId: 'xxx',
        batchId: '123',
        reportDate: Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time) 
    },
    { 
        licenseId: 'yyy',
        batchId: '124',
        reportDate: Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time) 
    },
    { 
        licenseId: 'aaa',
        batchId: '145',
        reportDate: Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time) 
    }
];

var finalResult = [
    { 
        reportDate: Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time),
        license: {},
        testType: 'P1',
        productType: 'Flower',
        batchId: '123',
        licenseId: 'xxx',
        createType: 'DataUpload' 
    },
    { 
        reportDate: Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time),
        testType: 'P1',
        productType: 'Flower',
        batchId: '124',
        licenseId: 'yyy',
        createType: 'DataUpload' 
    },
    { 
        reportDate: Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time),
        testType: 'P1',
        productType: 'Flower',
        batchId: '145',
        licenseId: 'aaa',
        createType: 'DataUpload' 
    },
    { 
        reportDate: Fri Dec 14 2015 00:00:00 GMT+0530 (India Standard Time),
        testType: 'P1',
        productType: 'Flower',
        batchId: '145',
        licenseId: 'zzz',
        createType: 'DataUpload' 
    }
]

我试图从 finalResult 对象中只获取不匹配的对象，最终结果将是这样的：

[
    { 
        reportDate: Fri Dec 14 2015 00:00:00 GMT+0530 (India Standard Time),
        testType: 'P1',
        productType: 'Flower',
        batchId: '145',
        licenseId: 'zzz',
        createType: 'DataUpload' 
    } 
]

我正在尝试这个，但没有得到正确的结果：

for(var j=0;j < duplicateTestData.length;j++){
    for (var i = 0; i < finalResult.length; i++) {
        if (
            (finalResult[i].licenseId == duplicateTestData[j].licenseId)  && 
            (finalResult[i].reportDate == duplicateTestData[j].reportDate) &&
            (finalResult[i].batchId == duplicateTestData[j].batchId)
        ) {
            finalResult.splice(i, 1);
            break;
        }
    }
}

console.log(finalResult);

Answer 1

var res = _.filter(finalResult, function(item) {
  return !_.find(duplicateTestData, {
    batchId: item.batchId,
    licenseId: item.licenseId,
    reportDate: item.reportDate
  });
});
console.log(res);

jsfiddle

Answer 2

你可以使用哈希 table 和 return 一个新的结果集，而不会在迭代时出现拼接数组的问题。

function getKey(o) {
    return o.licenseId + '|' + o.reportDate + '|' + o.batchId;
}

var duplicateTestData = [{ licenseId: 'xxx', batchId: '123', reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)' }, { licenseId: 'yyy', batchId: '124', reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)' }, { licenseId: 'aaa', batchId: '145', reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)' }],
    finalResult = [{ reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)', license: {}, testType: 'P1', productType: 'Flower', batchId: '123', licenseId: 'xxx', createType: 'DataUpload' }, { reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)', testType: 'P1', productType: 'Flower', batchId: '124', licenseId: 'yyy', createType: 'DataUpload' }, { reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)', testType: 'P1', productType: 'Flower', batchId: '145', licenseId: 'aaa', createType: 'DataUpload' }, { reportDate: 'Fri Dec 14 2015 00:00:00 GMT+0530 (India Standard Time)', testType: 'P1', productType: 'Flower', batchId: '145', licenseId: 'zzz', createType: 'DataUpload' }],
    hash = Object.create(null),
    result = [];

duplicateTestData.forEach(function (a) {            
    hash[getKey(a)] = true;
});

result = finalResult.filter(function (a) {
    return !hash[getKey(a)];
});

console.log(result);

ES6

function getKey(o) {
    return o.licenseId + '|' + o.reportDate + '|' + o.batchId;
}

var duplicateTestData = [{ licenseId: 'xxx', batchId: '123', reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)' }, { licenseId: 'yyy', batchId: '124', reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)' }, { licenseId: 'aaa', batchId: '145', reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)' }],
    finalResult = [{ reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)', license: {}, testType: 'P1', productType: 'Flower', batchId: '123', licenseId: 'xxx', createType: 'DataUpload' }, { reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)', testType: 'P1', productType: 'Flower', batchId: '124', licenseId: 'yyy', createType: 'DataUpload' }, { reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)', testType: 'P1', productType: 'Flower', batchId: '145', licenseId: 'aaa', createType: 'DataUpload' }, { reportDate: 'Fri Dec 14 2015 00:00:00 GMT+0530 (India Standard Time)', testType: 'P1', productType: 'Flower', batchId: '145', licenseId: 'zzz', createType: 'DataUpload' }],
    map = duplicateTestData.reduce((r, a) => r.set(getKey(a)), new Map),
    result = finalResult.filter(a => !map.has(getKey(a)));

console.log(result);

Answer 3

简单的出路

finalResult.filter(({batchId:a, licenseId:b, reportDate:c}) =>
  duplicateTestData.find(({batchId:x, licenseId:y, reportDate:z}) =>
    a === x && b === y && c === z) === undefined)

=> [ { reportDate: 'Fri Dec 14 2015 00:00:00 GMT+0530 (India Standard Time)',
    testType: 'P1',
    productType: 'Flower',
    batchId: '145',
    licenseId: 'zzz',
    createType: 'DataUpload' } ]

好的，有效，但这主要是垃圾。它没有完全准确地描述您要进行的比较。它太具体了，一旦你的数据发生变化，它就会崩溃。

继续阅读，我们可以学到一些有趣的东西。

所有（键和值）的对象平等......

我将从创建几个通用过程开始，我们可以使用它们来更好地描述问题的解决方案。

与其他解决方案相比，您会注意到此解决方案不对数据的内部结构做任何假设。此解决方案不关心对象中使用的实际键名。

这意味着我们不会触及任何 batchId、licenseId 或 reportDate。在这种情况下，通用过程可以解决所有问题，而最好的部分是您可以对要处理的任何数据反复使用它们。

// arrayCompare :: (a -> b -> Bool) -> [a] -> [b] -> Bool
const arrayCompare = f=> ([x,...xs])=> ([y,...ys])=> {
  if (x === undefined && y === undefined)
    return true
  else if (! f (x) (y))
    return false
  else
    return arrayCompare (f) (xs) (ys)
}

// keys :: Object(k:v) -> [k]
const keys = Object.keys

// objectCompare :: (v -> v -> Bool) -> Object(k:v) -> Object(k:v) -> Bool
const objectCompare = f=> a=> b=>
  arrayCompare (x=> y=> f (a[x]) (b[y]) && f (a[y]) (b[y])) (keys(a)) (keys(b))

// objectEqual :: Object -> Object -> Bool
const objectEqual = objectCompare (x=> y=> x === y)

// sample data
let xs = [
  {a:1,b:10},
  {a:2,b:20},
  {a:3,b:30}
]

let ys = [
  {a:1,b:10},
  {a:2,b:20},
  {a:3,b:30},
  {a:4,b:40}
]

// return all ys that are not present in xs
var result = ys.filter(y=> xs.find(objectEqual(y)) === undefined)

console.log(result)
// [{a:4,b:40}]

明白了！

您将不得不稍微调整此解决方案，因为您没有比较所有对象键。 finalResult 中的对象比 duplicateTestData 中的对象具有更多键，因此有零个 1:1 匹配项。

简单来说，如果 x = {a:1} 与 y = {a:1,b:2} 进行比较，您希望将其视为 "match"，只要 x 中的所有 key:values ] 匹配 y

中的所有 key:values

如果我们使用上面的 objectEquals 比较器，则不会从 finalResult 中过滤掉任何内容，因为没有对象会匹配在 duplicateTestData 中找到的对象。由于这不是您想要的，让我们定义一个适合您的情况的比较器……

// subsetObjectEquals :: Object -> Object -> Bool
const subsetObjectEquals = objectCompare (x=> y=> y === undefined || x === y)

// this time use subsetObjectEquals
var result = finalResult.filter(x=>
  duplicateTestData.find(subsetObjectEquals(x)) === undefined)

subsetObjectEquals 的工作方式有点不同。我真的想不出一个更好的名字，因为这是一个有点奇怪的比较。当 y 为 undefined 时，这意味着该值的键不存在于 "subset object" 中，因此不需要进行比较

subsetObjectEquals(a,b)
// returns true if all key:value pairs in `a` match all key:value pairs in `b`
// otherwise returns false

完整的工作示例

我附上了一个完整的片段，它实际使用了您问题中包含的输入数据。在这里展开它运行看看它是否有效

// arrayCompare :: (a -> b -> Bool) -> [a] -> [b] -> Bool
const arrayCompare = f=> ([x,...xs])=> ([y,...ys])=> {
  if (x === undefined && y === undefined)
    return true
  else if (! f (x) (y))
    return false
  else
    return arrayCompare (f) (xs) (ys)
}

// keys :: Object(k:v) -> [k]
const keys = Object.keys

// objectCompare :: (v -> v -> Bool) -> Object(k:v) -> Object(k:v) -> Bool
const objectCompare = f=> a=> b=>
  arrayCompare (x=> y=> f (a[x]) (b[x]) && f (a[y]) (b[y])) (keys(a)) (keys(b))

// objectEqual :: Object -> Object -> Bool
const objectEqual = objectCompare (x=> y=> x === y)

// subsetObjectEquals :: Object -> Object -> Bool
const subsetObjectEquals = objectCompare (x=> y=> y === undefined || x === y)

// your data
var duplicateTestData = [{ licenseId: 'xxx',
    batchId: '123',
    reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)' },
  { licenseId: 'yyy',
    batchId: '124',
    reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)' },
  { licenseId: 'aaa',
    batchId: '145',
    reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)' }
  ];

var finalResult = [ { reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)',
    license: {},
    testType: 'P1',
    productType: 'Flower',
    batchId: '123',
    licenseId: 'xxx',
    createType: 'DataUpload' },
    { reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)',
    testType: 'P1',
    productType: 'Flower',
    batchId: '124',
    licenseId: 'yyy',
    createType: 'DataUpload' },
    { reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)',
    testType: 'P1',
    productType: 'Flower',
    batchId: '145',
    licenseId: 'aaa',
    createType: 'DataUpload' },
    { reportDate: 'Fri Dec 14 2015 00:00:00 GMT+0530 (India Standard Time)',
    testType: 'P1',
    productType: 'Flower',
    batchId: '145',
    licenseId: 'zzz',
    createType: 'DataUpload' }               
]

// get all finalResult items that do not subsetObjectEqual items in duplicateTestData
var result = finalResult.filter(x=>
  duplicateTestData.find(subsetObjectEquals(x)) === undefined)

console.log(result)

Answer 4

for (var a = 0; a < duplicateTestData.length; a++) {
  var dt = duplicateTestData[a];
  var dtr = new Date(dt.reportDate + '');

  for (var b = 0; b < finalResult.length; b++) {
    var fr = finalResult[b];
    var frr = new Date(fr.reportDate + '');

    //define your logic how to match two objects
    if (dtr.getTime() !== frr.getTime() &&
      dt.batchId !== fr.batchId) {
      //object matched. remove it from array

      var removed = finalResult.splice(b, 1);
      console.log('items removed', removed);
    }
  }
}

//print finalResult array
for (var c = 0; c < finalResult.length; c++) {
  console.log(finalResult[c]);
}

Answer 5

使用 lodash：

duplicateTestData.reduce( _.reject, finalResult );

var duplicateTestData = [
    { 
        licenseId: 'xxx',
        batchId: '123',
        reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)' 
    },
    { 
        licenseId: 'yyy',
        batchId: '124',
        reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)' 
    },
    { 
        licenseId: 'aaa',
        batchId: '145',
        reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)' 
    }
];

var finalResult = [
    { 
        reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)',
        license: {},
        testType: 'P1',
        productType: 'Flower',
        batchId: '123',
        licenseId: 'xxx',
        createType: 'DataUpload' 
    },
    { 
        reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)',
        testType: 'P1',
        productType: 'Flower',
        batchId: '124',
        licenseId: 'yyy',
        createType: 'DataUpload' 
    },
    { 
        reportDate: 'Fri Dec 11 2015 00:00:00 GMT+0530 (India Standard Time)',
        testType: 'P1',
        productType: 'Flower',
        batchId: '145',
        licenseId: 'aaa',
        createType: 'DataUpload' 
    },
    { 
        reportDate: 'Fri Dec 14 2015 00:00:00 GMT+0530 (India Standard Time)',
        testType: 'P1',
        productType: 'Flower',
        batchId: '145',
        licenseId: 'zzz',
        createType: 'DataUpload' 
    }
]

console.log( duplicateTestData.reduce( _.reject, finalResult ) );

<script src="https://cdn.jsdelivr.net/lodash/4.15.0/lodash.min.js"></script>

这里的核心是_.reject(), which is the opposite of _.filter(): when passed an object it will use _.matches()做局部比较

至运行它对于duplicateTestData 中的每个条目我们可以使用.reduce()，标准数组函数。我们传入 finalResult 作为 initialValue。方便的是参数顺序正确，所以我们不需要匿名函数！（我真的应该说 lodash 是一个设计非常好的库。）一旦 reduce() 已经运行通过了 duplicateTestData 中的所有条目，它将 return 最终过滤结果。

如何使用 javascript 或 lodash 从对象数组中删除不匹配的对象

How to remove unmatched objects from array of objects using javascript or lodash

javascript

node.js

underscore.js

lodash

简单的出路

所有（键和值）的对象平等......

明白了！

完整的工作示例