If you're looking for assistance, consider this:
var rest = email.map(a => {
return a.firstPersonEmail;
});
console.log(rest);
or
var rest = email.map(a => a.firstPersonEmail);
console.log(rest);
const email = [
{id:1, firstPersonEmail: "<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="591336313719343830357734383035">[email protected]</a>"},
{id:2, firstPersonEmail: "<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="470d282f2975072a262e2b692a262e2b">[email protected]</a>"},
{id:3, firstPersonEmail: "<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="a4eecbccca97e4c9c5cdc88ac9c5cdc8">[email protected]</a>"}
];
const emptyEmail = [];
console.log(`Email length: ${email.length}`);
console.log(`Empty Email length: ${emptyEmail.length}`);
const rest = email.map(a => a.firstPersonEmail);
const emptyRest = emptyEmail.map(a => a.firstPersonEmail);
console.log(rest);
console.log(emptyRest);