[英]How to remove unmatched objects from array of objects using javascript or lodash
我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,最终结果如下:
[
{
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);
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, 它有效 ,但这主要是垃圾。 它没有完全准确地描述您正在尝试进行的比较。 它太具体了,一旦你的数据发生变化就会中断。
继续阅读,我们可以学到一些有趣的东西
我将首先制作几个通用程序,以便更好地描述我们问题的解决方案。
与其他解决方案相比,您对此解决方案的注意事项是,它不会对数据的内部结构做出任何假设。 此解决方案可能不关心对象中使用的实际键名称。
这意味着我们不会接触任何batchId
, licenseId
或reportDate
。 在这种情况下,通用程序可以解决所有问题,最好的部分是你可以反复使用它们来处理你想要处理的任何数据。
// 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}]
您必须稍微调整此解决方案,因为您没有比较所有对象键。 finalResult
对象比duplicateTestData
对象具有更多的键,因此没有1:1的匹配。
简单来说,如果将x = {a:1}
与y = {a:1,b:2}
进行比较,则需要将x = {a:1}
视为“匹配”,只要x
中的所有键:值与所有键匹配: y
值
如果我们使用objectEquals
上述比较,没有什么会被过滤掉的finalResult
因为没有对象将匹配找到对象duplicateTestData
。 由于这不是你想要的,让我们定义一个适用于你的情况的比较器......
// 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
工作方式subsetObjectEquals
不同。 我真的没想到一个更好的名字,因为这是一个有点奇怪的比较。 当y
undefined
,表示该值的键不存在于“子对象”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
我附上了一个完整的片段,它实际上使用了你问题中包含的输入数据。 在此处展开并运行它以查看它是否有效
// 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)
var res = _.filter(finalResult, function(item) {
return !_.find(duplicateTestData, {
batchId: item.batchId,
licenseId: item.licenseId,
reportDate: item.reportDate
});
});
console.log(res);
您可以使用哈希表并返回一个新的结果集,而不会在迭代时拼接数组。
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);
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]);
}
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>
其核心是_.reject()
,它与_.filter()
相反:当传递一个对象时,它将使用_.matches()
进行部分比较。
要为duplicateTestData中的每个条目运行它,我们可以使用.reduce()
,标准的Array函数。 我们将finalResult作为initialValue传递。 方便地,参数的顺序正确,因此我们不需要匿名函数! (我应该说lodash是一个设计得很好的库。)一旦reduce()
遍历duplicateTestData中的所有条目,它将返回最终的过滤结果。
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