JS求两个对象数组的差集

Question

let arr1 = [ 
    {fpcid: "2da37fdfe66140089dc3367b21cc6194", fpcNameCode: "34"},
    {fpcid: "2da37fdfe66140089dc3367b21cc6195", fpcNameCode: "33"},
    {fpcid: "2da37fdfe66140089dc3367b21cc6196", fpcNameCode: "35"},
    {fpcid: "2da37fdfe66140089dc3367b21cc6197", fpcNameCode: "36"}
];
let arr2 = [ 
    {fpcid: "2da37fdfe66140089dc3367b21cc6194", fpcNameCode: "34"},
    {fpcid: "2da37fdfe66140089dc3367b21cc6195", fpcNameCode: "33"}
];

JS求两个对象数组的差集

[
        {fpcid: "2da37fdfe66140089dc3367b21cc6196", fpcNameCode: "35"},
        {fpcid: "2da37fdfe66140089dc3367b21cc6197", fpcNameCode: "36"}
]

Answer 1

先上代码：

{
            let arr1 = [
                { fpcid: "2da37fdfe66140089dc3367b21cc6194", fpcNameCode: "34" },
                { fpcid: "2da37fdfe66140089dc3367b21cc6195", fpcNameCode: "33" },
                { fpcid: "2da37fdfe66140089dc3367b21cc6196", fpcNameCode: "35" },
                { fpcid: "2da37fdfe66140089dc3367b21cc6197", fpcNameCode: "36" }
            ];
            let arr2 = [
                { fpcid: "2da37fdfe66140089dc3367b21cc6194", fpcNameCode: "34" },
                { fpcid: "2da37fdfe66140089dc3367b21cc6195", fpcNameCode: "33" }
            ];
            
            function getDifferenceSetA(arr1, arr2) {
                arr1 = arr1.map(JSON.stringify);
                arr2 = arr2.map(JSON.stringify);
                return arr1.concat(arr2).filter(function (v, i, arr) {
                    return arr.indexOf(v) === arr.lastIndexOf(v);
                }).map(JSON.parse)
            }
            
            function getDifferenceSetB(arr1,arr2,typeName){
                return Object.values(arr1.concat(arr2).reduce((acc,cur) => {
                    if (acc[cur[typeName]] && acc[cur[typeName]][typeName] === cur[typeName]) {
                        delete acc[cur[typeName]];
                    }else{
                        acc[cur[typeName]] = cur;
                    }
                    return acc ;
                },{}));
            }
            

            console.log('getDifferenceSetA:',getDifferenceSetA(arr1,arr2));
            console.log('getDifferenceSetB:',getDifferenceSetB(arr1,arr2,'fpcid'));

        }

输出结果如下图：

两种方案比较，A方案比较取巧，使用起来方便快捷，但有个问题，对于值不为基础类型的对象可能产生一些不可预知的报错；
B方案比较稳定，可以适应各种对象比较，但写法和逻辑相对A稍微复杂点。

Answer 2

这个可以将数组项转成字符串来处理，以下为代码:

  
  console.log(((a = arr1.map(JSON.stringify),b = arr2.map(JSON.stringify))=>{ return a.concat(b).filter(c => !a.includes(c) || !b.includes(c)).map(JSON.parse)})())
  //可拆分成,arr1和arr2为你提供的数据数组
  function diffrence(a,b){
      a = a.map(JSON.stringify);
      b = b.map(JSON.stringify);
      return a.concat(b).filter(v => !a.includes(v) || !b.includes(v)).map(JSON.parse)
  }
  diffrence(arr1,arr2);
  

Answer 3

let arr1 = [ 
    {fpcid: "2da37fdfe66140089dc3367b21cc6194", fpcNameCode: "34"},
    {fpcid: "2da37fdfe66140089dc3367b21cc6195", fpcNameCode: "33"},
    {fpcid: "2da37fdfe66140089dc3367b21cc6196", fpcNameCode: "35"},
    {fpcid: "2da37fdfe66140089dc3367b21cc6197", fpcNameCode: "36"}
];
let arr2 = [ 
    {fpcid: "2da37fdfe66140089dc3367b21cc6194", fpcNameCode: "34"},
    {fpcid: "2da37fdfe66140089dc3367b21cc6195", fpcNameCode: "33"}
];

解决方法:

function getDiffCollection(arr1, arr2) {
    if(!Array.isArray(arr1) || !Array.isArray(arr2)) return null;
    
    const longArr = arr1.length > arr2.length ? arr1 : arr2;
    
    const diffCollect = longArr.reduce((acc, cv, index, arr) => {
        if(!arr1[index] || !arr2[index]) acc.push(cv)
        if(arr1[index] && arr2[index] && !equalObject(arr1[index], arr2[index])) acc.push(cv)
        return acc

    }, [])
    return diffCollect;
}

function equalObject(o1, o2) {
    for(const attr in o1) {
        if(o1.hasOwnProperty(attr)) {
            
            if(o1[attr] !== o2[attr]) return false
        }
    }
    return true
}

可能有些麻烦。有简单方法不舍赐教

Answer 4

对于这种值为基础类型的对象，可以试一下JSON.stringify()，转换成JSON字符串处理更方便点

Answer 5

这样试试。。。

let arr1 = [
  { fpcid: "2da37fdfe66140089dc3367b21cc6194", fpcNameCode: "34" },
  { fpcid: "2da37fdfe66140089dc3367b21cc6195", fpcNameCode: "33" },
  { fpcid: "2da37fdfe66140089dc3367b21cc6196", fpcNameCode: "35" },
  { fpcid: "2da37fdfe66140089dc3367b21cc6197", fpcNameCode: "36" }
];
let arr2 = [
  { fpcid: "2da37fdfe66140089dc3367b21cc6194", fpcNameCode: "34" },
  { fpcid: "2da37fdfe66140089dc3367b21cc6195", fpcNameCode: "33" }
];

function diffset(arr1, arr2) {
  var l, shortArr, longArr;
  if (arr1.length > arr2.length) {
    shortArr = arr2;
    longArr = JSON.parse(JSON.stringify(arr1));
  } else {
    shortArr = arr1;
    longArr = JSON.parse(JSON.stringify(arr2));
  }
  l = shortArr.length;
  for (var i = l - 1; i >= 0; i--) {
    let { fpcid, fpcNameCode } = shortArr[i]
    let t = longArr.findIndex(item => item.fpcid === fpcid && item.fpcNameCode === fpcNameCode)
    if (t < 0) {
      longArr.push(arr2[i])
    } else {
      longArr.splice(t, 1)
    }
  }
  return longArr;
}
console.table(diffset(arr1, arr2))