How to construct an array of object to unique array of object-CodePudding

I have an array of object like this

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'
    },
]

and my expect array of objects

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

CodePudding user response：

Just a simple for loop is probably the clearest. Here storing each object in a temp variable to avoid having to access the end of the result array every iteration, and abstracting the size into a variable.

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)

CodePudding user response：

How about a switch-case with a modulo % operator to check for the current key:

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'
    },
  ];
}

CodePudding user response：

According to your data,the top 3 records are property name,others are data,so we can use Array.slice() to get the property names

Then we can use Array.reduce() to convert the left data

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)