Example
In many cases I had to filter and modify arrays myself and sometimes join them together to a string.
[{"First name": "Henrik", "Last name": "Foo"}, {"First name": "Moritz", "Last name": "doo"}]
return input.filter( i => i['Last name']).map(i => `${i['First name']} ${i['Last name']}`).join('; ');
{ output: 'Henrik Foo; Moritz doo' }