javascript - 将字符串数组转换为 2 个类别和子类别数组

Question

我是网站上的新手，我有一个非常简单的 JS 问题，但我无法解决。
我有一个字符串数组:
像这样:

arr = [
"Economic_Working",
"Health_Excursions",
"Health_Doctors",
"Health_Meditation",
"Social_Religion",
"Social_Holidays"
]

我想成为 2 个这样的数组:

categoryArr = ["Economic" , "Health" , "Social" ];

subCategoryArr = [
["Working"] ,
[ "Meditation" , "Doctors" , "Excursions"] ,
[ "Religion" , "Holidays"]
 ];

第一个数组包含文本的第一部分，
在第二个数组中，我放置了第二部分，但根据第一个数组中属于其类别的索引
这就是我尝试做的:

let arr = [
"Economic_Working",
"Health_Excursions",
"Health_Doctors",
"Health_Meditation",
"Social_Religion",
"Social_Holidays"
]

let convertTo2Arrays = (array) => {
  let categoryArr = []
  array.map(item => {
   firstPart = item.split("_")[0];
   return categoryArr.push(firstPart)
  })
  
  return categoryArr;
}

console.log(convertTo2Arrays(arr))

Answer 1

您可以 reduce 数组并创建一个累加器对象，该对象将每个类别映射到子类别数组。然后，获取该对象的键和值

const arr = ["Economic_Working", "Health_Excursions", "Health_Doctors", "Health_Meditation", "Social_Religion", "Social_Holidays"];

const group = arr.reduce((acc, str) => {
  const [cat, subCat] = str.split('_');
  acc[cat] = acc[cat] || []
  acc[cat].push(subCat)
  return acc
}, {})

console.log( Object.keys(group) )
console.log( Object.values(group) )

reduce 返回的对象:

{
  "Economic": [ "Working" ],
  "Health": [ "Excursions", "Doctors", "Meditation" ],
  "Social": [ "Religion", "Holidays" ]
}