javascript - 在javascript中合并数组本身

Question

我的数组如下所示：

{"type":"send","name":"kebab","quantity":"1"},
{"type":"send","name":"potato","quantity":"25000"},
{"type":"receive","name":"money","quantity":"1"},
{"type":"receive","name":"soul","quantity":"12"},
{"type":"receive","name":"paper","quantity":"8"},
{"type":"send","name":"kebab","quantity":"1"},
{"type":"send","name":"potato","quantity":"25000"},
{"type":"receive","name":"money","quantity":"1"},
{"type":"receive","name":"soul","quantity":"12"},
{"type":"receive","name":"paper","quantity":"8"}

我希望它合并到将添加或减去值的新数组中，如下所示：

{"type":"send","name":"kebab","quantity":"2"},
{"type":"send","name":"potato","quantity":"50000"},
{"type":"receive","name":"money","quantity":"2"},
{"type":"receive","name":"soul","quantity":"24"},
{"type":"receive","name":"paper","quantity":"16"}

我不知道该怎么做

更新：类型和名称应该保持不变，只有数量会改变

标签： javascriptarrays

Answer 1

您可以将项目减少到一个新数组并将数量相加。

const items = [{"type":"send","name":"kebab","quantity":"1"},
{"type":"send","name":"potato","quantity":"25000"},
{"type":"receive","name":"money","quantity":"1"},
{"type":"receive","name":"soul","quantity":"12"},
{"type":"receive","name":"paper","quantity":"8"},
{"type":"send","name":"kebab","quantity":"1"},
{"type":"send","name":"potato","quantity":"25000"},
{"type":"receive","name":"money","quantity":"1"},
{"type":"receive","name":"soul","quantity":"12"},
{"type":"receive","name":"paper","quantity":"8"}]


let result = items.reduce((arr, item) => {
  // Find the item in the new array by name
  let found = arr.find(i => i.name == item.name && i.type == item.type)
  // If the item doesn't exist add it to the array
  if(!found) return arr.concat(item)
  // If the item does exist add the two quantities together
  // This will modify the value in place, so we don't need to re-add it
  found.quantity = parseFloat(item.quantity) + parseFloat(found.quantity)
  // Return the new state of the array
  return arr;
}, [])

console.log(result)