Bagaimanakah saya boleh mengumpulkan dan mengagregat objek dengan cekap dalam tatasusunan dengan berbilang sifat?

Efficiently Grouping and Aggregating objects in an Array by Multiple Properties

In this article, we address a critical task: Grouping objects within an array by multiple properties and aggregating their values.

The Challenge

Grouping objects in arrays based on multiple criteria can be a perplexing problem. While existing solutions can group objects by multiple keys, they often fail to effectively combine and eliminate duplicates. Our goal is to create a solution that seamlessly groups objects by shape and color, sums their respective 'used' and 'instances' values, and eliminates duplicates.

The Solution

Our approach utilizes the array.reduce() method in conjunction with a helper object. For each object in the array, we construct a unique key by concatenating its shape and color. We then check if this key exists in our helper object:

1. If the key exists, we simply increment the 'used' and 'instances' values of the corresponding object in the helper.
2. If the key does not exist, we create a new object with a copy of the original and add it to the helper object using Object.assign(). We also push this object into the result array.

By using a helper object to keep track of unique combinations of shape and color, we effectively group and aggregate objects while eliminating duplicates.

var arr = [{"shape":"square","color":"red","used":1,"instances":1},
{"shape":"square","color":"red","used":2,"instances":1},
{"shape":"circle","color":"blue","used":0,"instances":0},
{"shape":"square","color":"blue","used":4,"instances":4},
{"shape":"circle","color":"red","used":1,"instances":1},
{"shape":"circle","color":"red","used":1,"instances":0},
{"shape":"square","color":"blue","used":4,"instances":5},
{"shape":"square","color":"red","used":2,"instances":1}
];

var helper = {};
var result = arr.reduce(function(r, o) {
  var key = o.shape + '-' + o.color;

  if(!helper[key]) {
    helper[key] = Object.assign({}, o); // create a copy of o
    r.push(helper[key]);
  } else {
    helper[key].used += o.used;
    helper[key].instances += o.instances;
  }

  return r;
}, []);

console.log(result);

The Output

By implementing this solution, we obtain the desired result:

[{"shape":"square","color":"red","used":5,"instances":3},
{"shape":"circle","color":"red","used":2,"instances":1},
{"shape":"square","color":"blue","used":11,"instances":9},
{"shape":"circle","color":"blue","used":0,"instances":0}]

This effectively groups objects by shape and color, sums up their values, and removes duplicates.

Atas ialah kandungan terperinci Bagaimanakah saya boleh mengumpulkan dan mengagregat objek dengan cekap dalam tatasusunan dengan berbilang sifat?. Untuk maklumat lanjut, sila ikut artikel berkaitan lain di laman web China PHP!