推送到数组时，值被重复

Question

When I run this code I get the last element duplicated for all entries. I am trying to add a new role in discord and save some entries to my json file regarding role details idk but I can't seem to do it.

I have added the declarations for the data nd list variables.

let data = fs.readFileSync('roles.json')
var list = JSON.parse(data)
var details = {nickname:"",channel:"",message:"",role:"",emoji:"",raw:"",error:""}
let sections = ['A','B','C','D']
var bar = new Promise((resolve, reject) => {
            sections.forEach(async function (value, index, array) {
                    let role = await message.guild.roles.create({ data: { name: `Section ${value}` } })
                    details.nickname = value
                    details.channel = '12345567'
                    details.message = '1233454676'
                    details.role = role.id
                    details.error = '12443566'
                    list.push(details)
                    if (index === array.length - 1)
                        resolve()
                });
        });
        
        bar.then(() => {
            console.log(list);
        });

Output

[
  {
    nickname: '', 
    channel: '',  
    message: '',  
    role: '',     
    emoji: '',    
    raw: '',      
    error: ''     
  },
  {
    nickname: 'D',
    channel: '12345567',
    message: '1233454676',
    role: '784672976855498813',
    emoji: '',
    raw: '',
    error: '12443566'
  },
  {
    nickname: 'D',
    channel: '12345567',
    message: '1233454676',
    role: '784672976855498813',
    emoji: '',
    raw: '',
    error: '12443566'
  },
  {
    nickname: 'D',
    channel: '12345567',
    message: '1233454676',
    role: '784672976855498813',
    emoji: '',
    raw: '',
    error: '12443566'
  },
  {
    nickname: 'D',
    channel: '12345567',
    message: '1233454676',
    role: '784672976855498813',
    emoji: '',
    raw: '',
    error: '12443566'
  }
]

Answer 1

You are mutating the same object repeatedly before pushing a reference to it into the list array.

Either declare a new details object inside the forEach callback each iteration...

 let sections = ['A', 'B', 'C', 'D'] const list = [] sections.forEach((value) => { const details = {} details.nickname = value list.push(details) }); console.log(list)

...or if the above is not possible, push a clone of the details object into list instead of a reference to the original details object.

 let sections = ['A', 'B', 'C', 'D'] const list = [] const details = {} sections.forEach((value) => { details.nickname = value list.push({...details}) }); console.log(list)

Answer 2

use for...of instead, don't use async...await inside foreach loop