通过多个属性下划线对数组中的元素进行分组

Question

工作期间，我接到了这样的任务：对数组中具有相似属性的元素进行分组。

一般来说，问题如下：

var order = [
    {
        "tot":1,
        "ru":"R401",
        "area":"RFCC",
        "unit":"OFFSITE",
        "equipment":"37 P 552 A",
        "parameter":"Speed"
    }, {
        "tot":1,
        "ru":"R401",
        "area":"RFCC",
        "unit":"OFFSITE",
        "equipment":"37 P 552 A",
        "parameter":"Discharge pressure"
    }, {
        "tot":1,
        "ru":"R401",
        "area":"RFCC",
        "unit":"OFFSITE",
        "equipment":"37 P 552 A",
        "parameter":"Speed"
    }, {
        "tot":1,
        "ru":"R401",
        "area":"RFCC",
        "unit":"RCU",
        "equipment":"37 P 552 B",
        "parameter":"Discharge pressure"
    }
]

如果我按 'ru'、'area'、'unit'、'tot'、'equipment' 和 'parameter' 对这些元素进行分组，我将得到这个结果：

var result = [
    {
        "ru":"R401",
        "area":"RFCC",
        "unit":"OFFSITE",
        "tot":2,
        "equipment":"37 P 552 A",
        "parameter":"Speed"
    }, {
        "ru":"R401",
        "area":"RFCC",
        "unit":"OFFSITE",
        "tot":1,
        "equipment":"37 P 552 A",
        "parameter":"Discharge Pressure"
    }, {
        "ru":"R401",
        "area":"RFCC",
        "unit":"RCU",
        "tot":1,
        "equipment":"37 P 552 B",
        "parameter":"Discharge Pressure"
    }];

经过一些实验，我得出以下代码：

  var groups = _.groupBy(order, function(value) {
    return value.ru + "#" + value.area + "#" + value.unit + "#" + value.equipment + "#" + value.parameter + "#";
  });

  groups = _.map(groups, function(group) {
    return _.extend(group[0], {tot: group.length});
  });

现在我遇到了如何对相似的结果元素进行分组的问题。如果这附近有人，请帮助我。提前致谢。

Answer 1

这个怎么样：

var order = [
    {
        "tot":1,
        "ru":"R401",
        "area":"RFCC",
        "unit":"OFFSITE",
        "equipment":"37 P 552 A",
        "parameter":"Speed"
    }, {
        "tot":1,
        "ru":"R401",
        "area":"RFCC",
        "unit":"OFFSITE",
        "equipment":"37 P 552 A",
        "parameter":"Discharge pressure"
    }, {
        "tot":1,
        "ru":"R401",
        "area":"RFCC",
        "unit":"OFFSITE",
        "equipment":"37 P 552 A",
        "parameter":"Speed"
    }, {
        "tot":1,
        "ru":"R401",
        "area":"RFCC",
        "unit":"RCU",
        "equipment":"37 P 552 B",
        "parameter":"Discharge pressure"
    }
];
var result = [];
order.forEach(current=>{
    let index = -1;
    result.forEach((c,i)=>{
        if (c.ru==current.ru && c.area==current.area && c.unit==current.unit && c.tot==current.tot && c.equipment==current.equipment && c.parameter==current.parameter){
            index = i;
        }
    });
    // console.log(index);
    if(index==-1){
        result.push(current);
    }else{
        result[index]["tot"] = result[index]["tot"]+current["tot"];
    }
});
console.log(result);

Answer 2

也许你可以避免分组，直接更新你"index"map/object中合并对象的tot属性，如果你遇到类似的元素：

这是一个使用 reduce 实现的解决方案：

const order = [
    {
        "tot":1,
        "ru":"R401",
        "area":"RFCC",
        "unit":"OFFSITE",
        "equipment":"37 P 552 A",
        "parameter":"Speed"
    }, {
        "tot":1,
        "ru":"R401",
        "area":"RFCC",
        "unit":"OFFSITE",
        "equipment":"37 P 552 A",
        "parameter":"Discharge pressure"
    }, {
        "tot":1,
        "ru":"R401",
        "area":"RFCC",
        "unit":"OFFSITE",
        "equipment":"37 P 552 A",
        "parameter":"Speed"
    }, {
        "tot":1,
        "ru":"R401",
        "area":"RFCC",
        "unit":"RCU",
        "equipment":"37 P 552 B",
        "parameter":"Discharge pressure"
    }
]

const merged = Object.values(order.reduce((acc, curr) => {
  const key = `${curr.ru}#${curr.area}#${curr.unit}#${curr.equipment}#${curr.parameter}`;
  if (key in acc) acc[key].tot += 1;
  else acc[key] = Object.assign({}, curr);
  return acc;
}, {}));

console.log(merged);
console.log(merged.map(d => d.ru));

通过多个属性下划线对数组中的元素进行分组

Grouping elements in array by multiple properties underscore

javascript

arrays

json

underscore.js