#32 后端数据处理

ScriptOJ

从某数据库接口得到如下值：

{
  rows: [
    ["Lisa", 16, "Female", "2000-12-01"],
    ["Bob", 22, "Male", "1996-01-21"]
  ],
  metaData: [
    { name: "name", note: '' },
    { name: "age", note: '' },
    { name: "gender", note: '' },
    { name: "birthday", note: '' }
  ]
}

rows 是数据，metaData 是对数据的说明。现写一个函数 parseData，将上面的对象转化为期望的数组：

[
  { name: "Lisa", age: 16, gender: "Female", birthday: "2000-12-01" },
  { name: "Bob", age: 22, gender: "Male", birthday: "1996-01-21" },
]

本题来源：github

陈小俊

分享一下代码。。总感觉有更加简洁的写法

const parseData = (data) => {
  let arr = [];
  data.rows.map((row, index) => {
  	let obj = {};
  	row.map((ele, i) => {
  		obj[data.metaData[i].name] = ele

  	});
    arr.push(obj);
  });
  return arr;
}

CodeHz

@陈小俊

const parseData = ({rows, metaData}) => rows.map(row => row.reduce((p, c, i) => Object.assign({}, p, {[metaData[i].name]: c}), {}))

一行版

labike

const data = {
            rows: [
                ["Lisa", 16, "Female", "2000-12-01"],
                ["Bob", 22, "Male", "1996-01-21"]
            ],
            metaData: [{
                name: "name",
                note: ''
            }, {
                name: "age",
                note: ''
            }, {
                name: "gender",
                note: ''
            }, {
                name: "birthday",
                note: ''
            }]
        }
data.rows.map((row) => row.reduce((rowData, value, i) => {
	rowData[data.metaData[i].name] = value
	return rowData
}, {}))

Uncaught SyntaxError: Identifier 'data' has already been declared

这里用const data为什么会报错?

CodeHz

@labike data不应该是参数么，你又用const是为啥呢

labike

@CodeHz

假如你不把

{
            rows: [
                ["Lisa", 16, "Female", "2000-12-01"],
                ["Bob", 22, "Male", "1996-01-21"]
            ],
            metaData: [{
                name: "name",
                note: ''
            }, {
                name: "age",
                note: ''
            }, {
                name: "gender",
                note: ''
            }, {
                name: "birthday",
                note: ''
            }]
        }

赋给data,那么data.rows.map()里的data是哪里来的?

CodeHz

@labike 不是让你写成函数么。。。那个就是函数参数啊。。。而且测试用例里面的数据不止这一个，可能还是随机生成的。。

labike

@CodeHz

我为什么非要写成函数，为什么一定要让data作为函数的参数呢！你为什么不试试下面这个呢，这样并没有问题!

data.rows.map((row) => row.reduce((rowData, value, i) => {
	rowData[data.metaData[i].name] = value
	return rowData
}, {}))

const data ={}

ScriptOJ

@labike 因为题目要求写成函数

裂章

const parseData = data => {
  var keys = data.metaData.map(info=>info.name);
  return data.rows.map(row=>{
    var obj = {};
    keys.forEach((k,i)=>{
        obj[k] = row[i];
    });
    return obj;
  });
}

macro

const parseData = ({ rows, metaData }) =>
    rows.map(v => {
      const newObj = {}
      for (let i in v) {
        newObj[metaData[i].name] = v[i]
      }
      return newObj
 })

yyssjj33

简洁版

const parseData = (data) => {
  const metaDataArr = data['metaData'].map(d => d.name);
  const rows = data['rows'];
  return rows.map(row =>{
    return {
        [metaDataArr[0]]:row[0],
        [metaDataArr[1]]:row[1],
        [metaDataArr[2]]:row[2],
        [metaDataArr[3]]:row[3]
      }
    }
  )
}

宇宙人

const parseData = (data) => {
  let rows = data.rows;
  let metaData = data.metaData;
  let arr = [];
  rows.forEach((v) => {
    let obj = {};
    metaData.forEach((key, index) => {
      obj[key['name']] = v[index];
    });
    arr.push(obj);
  });
  return arr;
}

阿勒格鲁巴

const parseData = (data) => {
let resultArr = [];
data.rows.map((rowItem,rowsIndex) => {
let obj = {};
data.metaData.map((metaItem,metaIndex) => {
obj[metaItem.name] = rowItem[metaIndex];
});
resultArr.push(obj);
});
return resultArr;
}

湛瞳

forEach写法
const parseData = (data) => {
let a = []
data.rows.forEach(function(item, index) {
a[index] = {}
data.metaData.forEach(function(itemInner, indexInner) {
a[index][itemInner.name] = item[indexInner]
}, this);
}, this);
return a
}

lanaya

const parseData = (data) => data.rows.map(x => {
  return data.metaData.reduce((acc, meta, i) => ({ ...acc, [meta.name]: x[i] }) , {})
})

xingwenjun

es5写法
const parseData = (data) => {
var arr = []
for(var i =0;i<data.rows.length;i++){
var obj = {}
for (var j =0;j<data.metaData.length;j++){
obj[data.metaData[j].name] = data.rows[i][j]
}
arr.push(obj)
}
return arr
}

愤怒地小跑

const parseData = (data) => {
   var rows = data.rows, metaData = data.metaData, arr = [];
   for (let i = 0; i <= rows.length - 1; i++) {
       let obj = {};
       for (let j = 0; j <= rows[i].length - 1; j++) {
           obj[metaData[j].name] = rows[i][j];
       }
       arr.push(obj);
   }

   return arr;
};

Zendq1998

const parseData = (data) => {
return data.rows.map(item => data.metaData.reduce((obj, col, index) => obj[col.name] = item[index], {}))
}

Eddie

const parseData = (data) => {
  const {rows, metaData} = data
  return rows.map(item => {
    let obj = {}
    metaData.forEach((meta, index) => {
      obj[meta.name] = item[index]
    })
    return obj
  })
}