Question

我有一个以下格式的数组

cars = [
{id: 1, make: 'audi', year: '2010', someProperty: true},
{id: 2, make: 'bmw', year: '2011', someProperty: false},
{id: 3, make: 'bmw', year: '2011', someProperty: true},
{id: 4, make: 'vw', year: '2010', someProperty: true},
{id: 5, make: 'vw', year: '2011', someProperty: true},
{id: 6, make: 'audi', year: '2011', someProperty: true},
{id: 7, make: 'bmw', year: '2010', someProperty: false},
{id: 8, make: 'bmw', year: '2011', someProperty: false},
{id: 9, make: 'bmw', year: '2010', someProperty: true}
]

并将其转换为以下格式，

requiredFormat = [
  { 
    somePropertyTrue: [
      {id: 1, make: 'audi', year: '2010', someProperty: true},
      {id: 4, make: 'vw', year: '2010', someProperty: true},
      {id: 9, make: 'bmw', year: '2010', someProperty: true} 
    ],
    somePropertyFalse: [
      {id: 7, make: 'bmw', year: '2010', someProperty: false}
    ],
    year: '2010'
  }, 
  {
    somePropertyTrue: [
      {id: 3, make: 'bmw', year: '2011', someProperty: true},
      {id: 5, make: 'vw', year: '2011', someProperty: true},
      {id: 6, make: 'audi', year: '2011', someProperty: true}
    ],
    somePropertyFalse: [
      {id: 2, make: 'bmw', year: '2011', someProperty: false},
      {id: 8, make: 'bmw', year: '2011', someProperty: false}
    ],
    year: '2011'
  }
]

我正在使用如下转换功能，

function transform(cars) {
    return [...cars.reduce ( (acc, car) => {
        const yearGrp = acc.get(car.year) || { 
            somePropertyTrue: [], 
            somePropertyFalse: [],
            year: car.year
        };
        yearGrp['someProperty' + (car.someProperty ? 'True' : 'False')].push(car);
        return acc.set(car.year, yearGrp);
    }, new Map).values()];
}

我正在使用readline读取第一个数组并暂停每2000个项目，我正在尝试扩展上面的函数以接受先前转换的数组，以便将所有转换后的项目合并到一个数组中，我尝试了以下但我知道这不是解决这个问题的方法。

let transform = function transform(cars) {
    return [...cars.reduce((acc, arr) => {
        if (!first) {
            parsedArray.reduce((a) => {
                const yearGrp = a.get(arr.year) ||
                    acc.get(arr.year) || {
                        somePropertyTrue: [], 
                        somePropertyFalse: [],
                        year: arr.year
                    };
                yearGrp['someProperty' + (car.someProperty ? 'True' : 'False')].push(arr);
                return a.set(arr.year, yearGrp);
            });
        } else {
            const yearGrp = acc.get(arr.year) || {
                somePropertyTrue: [], 
                somePropertyFalse: [],
                year: arr.year
            };
            yearGrp['someProperty' + (car.someProperty ? 'True' : 'False')].push(arr);
            return acc.set(arr.year, yearGrp);
        }
    }, new Map())];
};

这里，parsedArray是我第一次尝试填充并尝试每隔一段时间使用它，'first'是一个标志

Answer 1

Array.prototype.reduce()解决方案：

＆＃13;

var cars = [
    {id: 1, make: 'audi', year: '2010', someProperty: true}, {id: 2, make: 'bmw', year: '2011', someProperty: false},
    {id: 3, make: 'bmw', year: '2011', someProperty: true}, {id: 4, make: 'vw', year: '2010', someProperty: true},
    {id: 5, make: 'vw', year: '2011', someProperty: true}, {id: 6, make: 'audi', year: '2011', someProperty: true},
    {id: 7, make: 'bmw', year: '2010', someProperty: false}, {id: 8, make: 'bmw', year: '2011', someProperty: false},
    {id: 9, make: 'bmw', year: '2010', someProperty: true}
],
requiredFormatData = [];
// grouping by 'year'
groups = cars.reduce(function(r, o){ 
    var k = 'someProperty' + ((o.someProperty)? 'True':'False');
    if (r[o.year]){	
    	(r[o.year][k]) && r[o.year][k].push(o) || (r[o.year][k] = [o]);
    } else {
    	r[o.year] = {year: o.year};
    	r[o.year][k] = [o];
        requiredFormatData.push(r[o.year]);
    }
    return r;
}, {});

console.log(requiredFormatData);

＆＃13;

Answer 2

最好保留地图/ id以便进一步插入数据。如果需要转换后的数据，可以从中获取快照。

您可以在地图上使用闭包并返回函数，例如

＆＃13;

company_name

＆＃13;

acc

＆＃13;

合并数组，同时在javascript中转换为不同的形式

2 个答案: