Javascript : How to get unique Id for multiple duplicate records

Question

假设我们有一个对象:

   var db = [
        {Id: "201" , Player: "Jon",price: "3.99", loc: "NJ" },
        {Id: "202", Player: "Sam",price: "4.22", loc: "PA" },
        {Id: "203" ,Player: "Sam",price: "4.22", loc: "NY" },
        {Id: "204", Player: "Bill",price: "3.22", loc: "TX" },
        {Id: "205" ,Player: "Dave",price: "3.99", loc: "WA" },
        {Id: "206" ,Player: "Dave",price: "3.99", loc: "WI" },
];

202,203,205,206 具有相似的播放器和价格值，但我只需要一个 ID 来表示相似的值，即输出应为 202,205。

Answer 1

您可以先使用 reduce() 返回包含每个 Player|price 组合计数的对象。然后你可以使用另一个 reduce，并检查 Player|price 的计数是否为 > 1。如果是，则将对象 id 添加到数组。

var db = [
   {Id: "201" ,Player: "Jon",price: "3.99", loc: "NJ" },
   {Id: "202", Player: "Sam",price: "4.22", loc: "PA" },
   {Id: "203" ,Player: "Sam",price: "4.22", loc: "NY" },
   {Id: "204", Player: "Bill",price: "3.22", loc: "TX" },
   {Id: "205" ,Player: "Dave",price: "3.99", loc: "WA" },
   {Id: "206" ,Player: "Dave",price: "3.99", loc: "WI" },
];

var obj = db.reduce(function(o, e) {
  o[e.Player + '|' + e.price] = (o[e.Player + '|' + e.price] || 0) + 1;
    return o;
}, {});

var result = db.reduce(function(r, e) {
  if(obj[e.Player + '|' + e.price] > 1) r.push(e.Id);
    return r;
}, []);

console.log(result)