const arr = ['f','m','e','s','k'];
const json = [
{
"_id": "60618c79b97bc12dbec866ed",
"name": "Mack Sampson"
},
{
"_id": "60618c79ea651080267b5e95",
"name": "Santana Wagner"
},
{
"_id": "60618c7985618a0dcef90469",
"name": "Holly Ferrell"
},
]
for (let user of json) {
if(arr. includes(user. name[0].toLoweCase () ) ){
console.log(
user.name);
}
}