Prevent .map from returning undefined for values that don’t meet a certain criteria
I have the following code:
const fetchUsers = async () => {
const users = [
{ id: 27, email: '[email protected]' },
{ id: 12754, email: '[email protected]' },
{ id: 12158, email: '[email protected]' },
{ id: 698115737, email: '[email protected]' },
]
const userAccessTable =
[
{
id: 12754,
WorkEmail: '[email protected]',
ClubNumber: '7908'
},
{
id: 12158,
WorkEmail: '[email protected]',
ClubNumber: '7729'
},
{
id: 4040,
WorkEmail: '[email protected]',
ClubNumber: '6437'
},
{
id: 4040,
WorkEmail: '[email protected]',
ClubNumber: '6438'
},
]
const userAccess = await Promise.all(
users.map(user => {
let res
userAccessTable.map(data => {
if (data.WorkEmail.toLowerCase().includes(user.email)) {
return res = {
userId: user.id,
club: data.ClubNumber,
email: data.WorkEmail
}
}
})
return res
})
)
console.log(userAccess)
}
fetchUsers()
I am trying to cross-reference the users with the userAccessTable and if they have the same email set the object to a variable, but because I am currently doing so while mapping I get the following output:
[
undefined,
{ userId: 12754, club: '7908', email: '[email protected]'},
{ userId: 12158, club: '7729', email: '[email protected]' },
undefined
]
is there a way to prevent the undefined values from coming back for the results that don’t have a similar email? here is a repl.it link https://repl.it/join/pvnetqkc-rterrell25
Answer
Ciao, you could initialize res to an empty object like this:
const users = [
{ id: 27, email: '[email protected]' },
{ id: 12754, email: '[email protected]' },
{ id: 12158, email: '[email protected]' },
{ id: 698115737, email: '[email protected]' },
]
const userAccessTable =
[
{
id: 12754,
WorkEmail: '[email protected]',
ClubNumber: '7908'
},
{
id: 12158,
WorkEmail: '[email protected]',
ClubNumber: '7729'
},
{
id: 4040,
WorkEmail: '[email protected]',
ClubNumber: '6437'
},
{
id: 4040,
WorkEmail: '[email protected]',
ClubNumber: '6438'
},
]
let result = users.map(user => {
let res = {}
userAccessTable.map(data => {
if (data.WorkEmail.toLowerCase().includes(user.email)) {
return res = {
userId: user.id,
club: data.ClubNumber,
email: data.WorkEmail
}
}
})
return res
})
console.log(result)Or you could filter your final result like this:
const users = [
{ id: 27, email: '[email protected]' },
{ id: 12754, email: '[email protected]' },
{ id: 12158, email: '[email protected]' },
{ id: 698115737, email: '[email protected]' },
]
const userAccessTable =
[
{
id: 12754,
WorkEmail: '[email protected]',
ClubNumber: '7908'
},
{
id: 12158,
WorkEmail: '[email protected]',
ClubNumber: '7729'
},
{
id: 4040,
WorkEmail: '[email protected]',
ClubNumber: '6437'
},
{
id: 4040,
WorkEmail: '[email protected]',
ClubNumber: '6438'
},
]
let result = users.map(user => {
let res
userAccessTable.map(data => {
if (data.WorkEmail.toLowerCase().includes(user.email)) {
return res = {
userId: user.id,
club: data.ClubNumber,
email: data.WorkEmail
}
}
})
return res
})
console.log(result.filter(el => el !== undefined))EDIT
To avoid empty object on result you could use forEach instead of map like:
const users = [
{ id: 27, email: '[email protected]' },
{ id: 12754, email: '[email protected]' },
{ id: 12158, email: '[email protected]' },
{ id: 698115737, email: '[email protected]' },
]
const userAccessTable =
[
{
id: 12754,
WorkEmail: '[email protected]',
ClubNumber: '7908'
},
{
id: 12158,
WorkEmail: '[email protected]',
ClubNumber: '7729'
},
{
id: 4040,
WorkEmail: '[email protected]',
ClubNumber: '6437'
},
{
id: 4040,
WorkEmail: '[email protected]',
ClubNumber: '6438'
},
]
let result = [];
users.forEach(user => {
let res = {}
userAccessTable.forEach(data => {
if (data.WorkEmail.toLowerCase().includes(user.email)) {
res = {
userId: user.id,
club: data.ClubNumber,
email: data.WorkEmail
}
result.push(res)
}
})
})
console.log(result)