将 JSON 对象键转换为小写

Question

所以我有以下 JSON 对象：var myObj = {   Name: "Paul",   Address: "27 Light Avenue"}我想将其键转换为小写，这样我会得到：var newObj = {   name: "Paul",   address: "27 Light Avenue"}我尝试了以下方法：var newObj = mapLower(myObj, function(field) {    return field.toLowerCase();})function mapLower(obj, mapFunc) {    return Object.keys(obj).reduce(function(result,key) {         result[key] = mapFunc(obj[key])         return result;    }, {})}但我收到一条错误消息“Uncaught TypeError: field.toLowerCase is not a function”。

Answer 1

我真的不确定你想用你的函数做什么，mapLower但你似乎只传递一个参数，即对象值。

尝试这样的事情（不是递归）

var myObj = {

   Name: "Paul",

   Address: "27 Light Avenue"

}

const t1 = performance.now()

const newObj = Object.fromEntries(Object.entries(myObj).map(([ key, val ]) =>

  [ key.toLowerCase(), val ]))

const t2 = performance.now()

console.info(newObj)

console.log(`Operation took ${t2 - t1}ms`)

这将获取所有对象条目（键/值对的数组），并将它们映射到键小写的新数组，然后从这些映射条目创建新对象。

如果您需要它来处理嵌套对象，您将需要使用递归版本

var myObj = {

  Name: "Paul",

  Address: {

    Street: "27 Light Avenue"

  }

}

// Helper function for detection objects

const isObject = obj => 

  Object.prototype.toString.call(obj) === "[object Object]"

// The entry point for recursion, iterates and maps object properties

const lowerCaseObjectKeys = obj =>

  Object.fromEntries(Object.entries(obj).map(objectKeyMapper))

  

// Converts keys to lowercase, detects object values

// and sends them off for further conversion

const objectKeyMapper = ([ key, val ]) =>

  ([

    key.toLowerCase(), 

    isObject(val)

      ? lowerCaseObjectKeys(val)

      : val

  ])

const t1 = performance.now()

const newObj = lowerCaseObjectKeys(myObj)

const t2 = performance.now()

console.info(newObj)

console.log(`Operation took ${t2 - t1}ms`)

Answer 2

这将解决您的问题：

var myObj = {

   Name: "Paul",

   Address: "27 Light Avenue"

}

let result = Object.keys(myObj).reduce((prev, current) => 

({ ...prev, [current.toLowerCase()]: myObj[current]}), {})

console.log(result)

Answer 3

var myObj = {

   Name: "Paul",

   Address: "27 Light Avenue"

}

Object.keys(myObj).map(key => {

  if(key.toLowerCase() != key){

    myObj[key.toLowerCase()] = myObj[key];

    delete myObj[key];

  }

});

console.log(myObj);

Answer 4

使用json-case-convertor

const jcc = require('json-case-convertor')

var myObj = {

   Name: "Paul",

   Address: "27 Light Avenue"

}

const lowerCase = jcc.lowerCaseKeys(myObj)

包链接： https: //www.npmjs.com/package/json-case-convertor