如何获取数组中唯一值的属性？

Question

正在编辑问题。从图片中我如何在一个对象中创建一个数组，以便我得到的数据如下：

  { Access Panel: [Step 1, Step 2], 
   Air Extraction: [Step 1] }

点击数组进行过滤，然后根据文本框中的输入输出唯一的 'Subnames'。我如何循环遍历原始数组，我相信我需要创建 key/value 对？不知道该怎么办。目标是填充 1 'Access Panel' 按钮，以便在单击时填充第 1 步和第 2 步。

已删除照片

Answer 1

使用Array.forEach()函数：

const arr = [
   {subname: "Access Panel", stepnum: "Step 1"},
   {subname: "Access Panel", stepnum: "Step 2"},
   {subname: "Access Panel", stepnum: "Step 3"},
   {subname: "Air Extraction", stepnum: "Step 1"},
   {subname: "Air Extraction", stepnum: "Step 2"},
   {subname: "Random", stepnum: "Step 1"}
];

const obj = {};
arr.forEach((el) => { 
  if(!obj[el.subname]){
    obj[el.subname] = [el.stepnum];
  }else{
    obj[el.subname].push(el.stepnum);
  }
});

console.log(obj);

更新：

与Array.reduce()：

const arr = [
   {subname: "Access Panel", stepnum: "Step 1"},
   {subname: "Access Panel", stepnum: "Step 2"},
   {subname: "Access Panel", stepnum: "Step 3"},
   {subname: "Air Extraction", stepnum: "Step 1"},
   {subname: "Air Extraction", stepnum: "Step 2"},
   {subname: "Random", stepnum: "Step 1"}
];

const res = arr.reduce((obj,el) => {
  obj[el.subname] = obj[el.subname] ? obj[el.subname].concat(el.stepnum) : [el.stepnum];
  return obj;
},{});

console.log(res);

如何获取数组中唯一值的属性？

How to get the properties of the unique values in array?

javascript

arrays

reactjs