如何將 object 的數組構造為 object 的唯一數組

Question

我有一個這樣的數組 object

let data = 
[
    {
        text: 'label'
    },
    {
        text: 'username'
    },
    {
        text: 'category'
    },
    {
        text: 'book'
    },
    {
        text: 'john'
    },
    {
        text: 'education'
    },
    {
        text: 'car'
    },
    {
        text: 'doe'
    },
    {
        text: 'automotive'
    },
    {
        text: 'shoes'
    },
    {
        text: 'cena'
    },
    {
        text: 'fashion'
    },
]

和我期望的對象數組

let result = 
[
    {
        label: 'book',
        username: 'john',
        category: 'education'
    },
    {
        label: 'car',
        username: 'doe',
        category: 'automotive'
    },
    {
        label: 'shoes',
        username: 'cena',
        category: 'fashion'
    },
]

Answer 1

只是一個簡單for循環可能是最清楚的。 這里將每個 object 存儲在一個temp變量中，以避免每次迭代都必須訪問結果數組的末尾，並將size抽象為一個變量。

 let data = [{ text: 'label' }, { text: 'username' }, { text: 'category' }, { text: 'book' }, { text: 'john' }, { text: 'education' }, { text: 'car' }, { text: 'doe' }, { text: 'automotive' }, { text: 'shoes' }, { text: 'cena' }, { text: 'fashion' },]; const size = 3; const result = []; for (let temp, i = size; i < data.length; i++) { if (i % size === 0) { result.push(temp = {}); } temp[data[i % size].text] = data[i].text; } console.log(result)

Answer 2

帶有模%運算符的switch-case如何檢查當前密鑰：

 const transformData = (data) => { let result = []; let tmpObj = {}; data.forEach((element, idx) => { switch (idx % 3) { case 0: tmpObj["label"] = element.text; break; case 1: tmpObj["username"] = element.text; break; case 2: result.push({...tmpObj, category: element.text }); tmpObj = {}; break; default: break; } }); return result; }; console.log(transformData(getSampleData())); function getSampleData() { return [{ text: 'label' }, { text: 'username' }, { text: 'category' }, { text: 'book' }, { text: 'john' }, { text: 'education' }, { text: 'car' }, { text: 'doe' }, { text: 'automotive' }, { text: 'shoes' }, { text: 'cena' }, { text: 'fashion' }, ]; }

Answer 3

根據你的數據，前3條記錄是屬性名，其他是數據，所以我們可以使用Array.slice()來獲取屬性名

然后我們可以使用Array.reduce()來轉換左邊的數據

let keys = data.slice(0,3).map(v => v.text)
let result = data.slice(3).reduce((a,c,i) =>{
  let key = keys[i%3]
  if(i%keys.length ==0){
   let obj = {}
   obj[key] = c.text
   a.push(obj)
  }else{
   a.at(-1)[key]=c.text
  }
  return a
},[])

console.log(result)

 let data = [ { text: 'label' }, { text: 'username' }, { text: 'category' }, { text: 'book' }, { text: 'john' }, { text: 'education' }, { text: 'car' }, { text: 'doe' }, { text: 'automotive' }, { text: 'shoes' }, { text: 'cena' }, { text: 'fashion' }, ] let keys = Object.values(data.slice(0,3)).map(v => v.text) let result = data.slice(3).reduce((a,c,i) =>{ let key = keys[i%3] if(i%keys.length ==0){ let obj = {} obj[key] = c.text a.push(obj) }else{ a.at(-1)[key]=c.text } return a },[]) console.log(result)