javascript - Doesn't the simplest form of arrow function return an object? map(i => { name: i})

Question

If the arrow function does not use curly braces{}, it is equivalent to returning directly

const arr = [1, 2, 3, 4]
arr.map(i => i) // 1 ,2 ,3, 4

But if I want to return an object, I cannot use the simplest form?

arr.map(i => { a: i}) // [undefined, undefined, undefined, undefined]

Must be enclosed in curly braces

arr.map(i => return {{ a: i}}) //  [Object, Object, Object, Object]

Answer 1

Definitely cannot use {} directly, because the function body is also implemented using {}, which will be considered to have an a:1expression

in the function body.

The simplest way to write it is to wrap it with ()

arr.map(i => ({a: i}))

Answer 2

arr.map(i => ({ a: i}))