Angular-如何使用求和和分组

由 Max发布于 2020-05-18 15:47:05

我需要根据ID对记录进行分组并显示权重之和。有人可以让我知道Angular中的总和和分组方法吗？

API响应：

data = [
  {Id:1, name: 'ABC', weight: 10 },
  {Id:1, name: 'ABC', weight: 14 },
  {Id:1, name: 'ABC', weight: 16 },
  {Id:2, name: 'DEF', weight: 23 },
  {Id:2, name: 'DEF', weight: 22 },
  {Id:4, name: 'GHI', weight: 44 },
  {Id:4, name: 'GHI', weight: 41 }
]

预期产量：

dataResult =  [
      {Id:1, name: 'ABC', weight: 40 },
      {Id:2, name: 'DEF', weight: 45 },
      {Id:4, name: 'GHI', weight: 85 }
    ]

回忆那么真

2020-05-18 15:47:06

请尝试这种方法

data = [
  {Id:1, name: 'ABC', weight: 10 },
  {Id:1, name: 'ABC', weight: 14 },
  {Id:1, name: 'ABC', weight: 16 },
  {Id:2, name: 'DEF', weight: 23 },
  {Id:2, name: 'DEF', weight: 22 },
  {Id:4, name: 'GHI', weight: 44 },
  {Id:4, name: 'GHI', weight: 41 }
]
var holder = {};

data.forEach(function(d) {
  if (holder.hasOwnProperty(d.name)) {
    holder[d.name] = holder[d.name] + d.weight;
  } else {
    holder[d.name] = d.weight;
  }
});

var obj2 = [];

for (var prop in holder) {
  obj2.push({ name: prop, value: holder[prop] });
}

console.log(obj2)

son

2020-05-18 15:47:06

You can use Array.reduce() to iterate over and Array.find() to find item by id. Then you can calculate the sum as followings:

const data = [
  {Id:1, name: 'ABC', weight: 10 },
  {Id:1, name: 'ABC', weight: 14 },
  {Id:1, name: 'ABC', weight: 16 },
  {Id:2, name: 'DEF', weight: 23 },
  {Id:2, name: 'DEF', weight: 22 },
  {Id:4, name: 'GHI', weight: 44 },
  {Id:4, name: 'GHI', weight: 41 }
]

const calculated = data.reduce((acc, item) => {
  
  let accItem = acc.find(ai => ai.Id === item.Id)
  
  if(accItem){
      accItem.weight += item.weight 
  }else{
     acc.push(item)
  }

  return acc;
},[])

console.log(calculated)

Max

这家伙很懒，什么都没留下

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