从对象数组中删除元素javascript

Question

我有以下对象数组。

[{"rId":24,"gId":40,"sId":20,"disabled":false},
 {"rId":24,"gId":40,"sId":19,"disabled":false},
 {"rId":24,"gId":40,"sId":50,"disabled":false},
 {"rId":24,"gId":40,"sId":20,"disabled":true},
 {"rId":24,"gId":40,"sId":19,"disabled":true},
 {"rId":24,"gId":40,"sId":50,"disabled":true},
 {"rId":24,"gId":39,"sId":18,"disabled":false}]

其中一些记录是对立的。第一个元素和第四个元素具有相同的 rId、gId 和 sId 但禁用标志相反。 我想消除所有这些记录。

我的预期数组是{"rId":24,"gId":39,"sId":18,"disabled":false}（消除所有对立记录）

我尝试了以下代码，但它给了我错误的输出。

arrOfObj=[{"rId":24,"gId":40,"sId":20,"disabled":false},
 {"rId":24,"gId":40,"sId":19,"disabled":false},
 {"rId":24,"gId":40,"sId":50,"disabled":false},
 {"rId":24,"gId":40,"sId":20,"disabled":true},
 {"rId":24,"gId":40,"sId":19,"disabled":true},
 {"rId":24,"gId":40,"sId":50,"disabled":true},
 {"rId":24,"gId":39,"sId":18,"disabled":false}]


$.each(arrOfObj,function (index1,firstObj) {
    $.each(arrOfObj,function (index2,secondObj) {
        if(index1>= index2){
            return true;
        }
        var areObjAntithesis=firstObj.rId===secondObj.rId && firstObj.gId===secondObj.gId
           && firstObj.sId===secondObj.sId && firstObj.disabled!==secondObj.disabled;

        if(areObjAntithesis){
            arrOfObj.splice(index1,1);
            arrOfObj.splice(index2,1)
            return false;
        }
    })
})

有什么优雅的方法可以达到预期的输出吗？

Answer 1

您可以使用 map() 和 filter() 来做到这一点

var data = [{"rId":24,"gId":40,"sId":20,"disabled":false},
 {"rId":24,"gId":40,"sId":19,"disabled":false},
 {"rId":24,"gId":40,"sId":50,"disabled":false},
 {"rId":24,"gId":40,"sId":20,"disabled":true},
 {"rId":24,"gId":40,"sId":19,"disabled":true},
 {"rId":24,"gId":40,"sId":50,"disabled":true},
 {"rId":24,"gId":39,"sId":18,"disabled":false}]
 
var ar = data.map(function(e) {
  return e.rId + '|' + e.gId + '|' + e.sId;
});
 
var result = data.filter(function(e) {
  var key = e.rId + '|' + e.gId + '|' + e.sId;
  return ar.indexOf(key) == ar.lastIndexOf(key);
});

console.log(result)

Answer 2

使用http://underscorejs.org/#where 并这样做：

var newArrOfObj=_.where(arrOfObj, {disabled:true});

Answer 3

您可以使用多个array.filter 并检查计数，并且仅返回值超过 1 个且值相同或只有一个值的元素

var data = [{"rId":24,"gId":40,"sId":20,"disabled":false},
 {"rId":24,"gId":40,"sId":19,"disabled":false},
 {"rId":24,"gId":40,"sId":50,"disabled":false},
 {"rId":24,"gId":40,"sId":20,"disabled":true},
 {"rId":24,"gId":40,"sId":19,"disabled":true},
 {"rId":24,"gId":40,"sId":50,"disabled":true},
 {"rId":24,"gId":39,"sId":18,"disabled":false}]

var result = data.filter(function(outer){
  var disablesValues = []
  
  var _r = data.filter(function(inner){
    if(inner.gId === outer.gId && inner.sId === outer.sId){
      if(disablesValues.indexOf(inner.disabled) < 0)
        disablesValues.push(inner.disabled);
      return true;
    }
  });
  
  return _r.length === 1 || disablesValues.length === 1
});

console.log(result)

Answer 4

这是函数式编程风格的 ES6 解决方案，它也将处理更多的重复，计算禁用和启用对象的数量如何相互平衡：

function eliminateOpposites(arr) {
    return [...arr
        .map( o => ({ o, k: JSON.stringify({ rId:o.rId, gId:o.gId, sId:o.sId }) }) )
        .reduce( (acc, o) => acc.set(o.k, (acc.get(o.k) || 0)+ (+o.o.disabled || -1)),
                             new Map() )]
        .filter( ([k, balance]) => balance )
        .map( ([k, balance]) => Object.assign(JSON.parse(k), {disabled: balance>0}));
}

// Sample data
var arrOfObj=[
 {"rId":24,"gId":40,"sId":20,"disabled":false},
 {"rId":24,"gId":40,"sId":19,"disabled":false},
 {"rId":24,"gId":40,"sId":50,"disabled":false},
 {"rId":24,"gId":40,"sId":20,"disabled":true},
 {"rId":24,"gId":40,"sId":19,"disabled":true},
 {"rId":24,"gId":40,"sId":50,"disabled":true},
 {"rId":24,"gId":39,"sId":18,"disabled":false}]
 
console.log(eliminateOpposites(arrOfObj));

它利用散列，这导致 O(n) 算法而不是 O(n²)，indexOf 风格的解决方案就是这种情况.

JSON.stringify 和JSON.parse 用于组合和分解组合键值。字符串版本用作Map 中的键，其中每个条目记录相同键的禁用与启用次数。 .filter() 调用排除了禁用和启用的次数相同的情况（可能是 2 对 2），最后的 .map() 将 kay/value 数组转换回预期的格式。

Answer 5

您可以使用两个循环，一个用于收集数组，一个用于过滤数组。

var data = [{ "rId": 24, "gId": 40, "sId": 20, "disabled": false }, { "rId": 24, "gId": 40, "sId": 19, "disabled": false }, { "rId": 24, "gId": 40, "sId": 50, "disabled": false }, { "rId": 24, "gId": 40, "sId": 20, "disabled": true }, { "rId": 24, "gId": 40, "sId": 19, "disabled": true }, { "rId": 24, "gId": 40, "sId": 50, "disabled": true }, { "rId": 24, "gId": 39, "sId": 18, "disabled": false }],
    hash = Object.create(null),
    getKey = function (o) { return ["rId", "gId", "sId"].map(function (k) { return o[k]; }).join('|'); },
    result;

data.forEach(function (a) {
    var key = getKey(a);
    hash[key] = (hash[key] || 0) + (a.disabled || -1);
});

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

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

ES6 与 Array#find

var data = [{ "rId": 24, "gId": 40, "sId": 20, "disabled": false }, { "rId": 24, "gId": 40, "sId": 19, "disabled": false }, { "rId": 24, "gId": 40, "sId": 50, "disabled": false }, { "rId": 24, "gId": 40, "sId": 20, "disabled": true }, { "rId": 24, "gId": 40, "sId": 19, "disabled": true }, { "rId": 24, "gId": 40, "sId": 50, "disabled": true }, { "rId": 24, "gId": 39, "sId": 18, "disabled": false }],
    result = data.filter(a =>
        !data.find(b => ["rId", "gId", "sId"].every(k => 
            a[k] === b[k]
        ) && a.disabled !== b.disabled));

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }