map()
the array to Object.values
and pass it to Object.fromEntries()
const arr = [ { field: "firstname", value: "John" }, { field: "lastname", value: "Doe" }, { field: "hobbies", value: "singing, basketball" }, ]
const res = Object.fromEntries(arr.map(Object.values))
console.log(res)
The another solution could be using reduce()
const arr = [ { field: "firstname", value: "John" }, { field: "lastname", value: "Doe" }, { field: "hobbies", value: "singing, basketball" }, ]
const res = arr.reduce((ac,a) => (ac[a.field] = a.value,ac),{})
console.log(res)