js对象属性名驼峰式转下划线的实例代码

let obj = {Id1: 1, idName1: 2, idAgeName1: 3};
let arr = []
function strReplace(str) {
  const UP_CASE_REG =/[A-Z]/g;
  const NUMBER_REG=/[A-Za-z][\d]/g
  let newstr = ""
  getIndex(UP_CASE_REG, str)
  getIndex(NUMBER_REG, str)
  arr.sort((a,b)=> a-b )
  for(let i = 0;i < arr.length; i ++) {
    if(i === 0) {
      newstr += str.slice(0,arr[i]) + "_"
    }
    else {
      newstr += str.slice(arr[i-1],arr[i]) + "_"
    }
  }
  newstr += str.slice(arr[arr.length-1])
  return newstr.toLowerCase()
}
function getIndex(reg, str) {
  do{
    reg.test(str)
    if(reg.lastIndex !== 0 && reg.lastIndex-1 !== 0){//reg.lastIndex-1 !== 0判断首字母是否大写
      arr.push(reg.lastIndex-1)
    }
  }while(reg.lastIndex > 0)
}
 
function strAllReplace(obj) {
  let newObj = {}
  Object.entries(obj).forEach(([key, value]) =>
  {
   newObj[strReplace(key)] = value
   arr = []
  })
  return newObj
}
console.log(strAllReplace(obj))//{id_1: 1, id_name_1: 2, id_age_name_1: 3}

const name = {
      first:"hello",
      last:"world",
      fullname: "hello world"
    }

for (var i of Object.keys(name)) {
        console.log(i,"-",name[i])
      }

function map(item) {
      for (var i of Object.keys(item)) {
        yield [i,item[i]]
      }
    }
    for(var [key, value] of map(name)) {
      console.log(key,"-",value)
    }

map = (item) => {
      for (var i of Object.keys(item)) {
        yield [i,item[i]]
      }
    }