javascript object literal dynamic key SyntaxError

Question

What is wrong with this expression?

['a', 'b'].map((x) => {[x]:x})

I'm getting this error:

Uncaught SyntaxError: Unexpected token :

score 7 · Accepted Answer · answered Jun 26 '18 at 15:12

7

You need to wrap your {} in (), or it will be interpreted as the body of a function:

['a', 'b'].map((x) => ({[x]: x }))

answered Jun 26 '18 at 15:12

Tholle

This is the correct answer. As a side note, for clarity, I often wrap the returned object like this: `['a', 'b'].map((x) => Object({[x]: x}))` – zfrisch Jun 26 '18 at 15:17

score 4 · Answer 2 · answered Jun 26 '18 at 15:12

4

You have enclosed the return value with ()

let result = ['a', 'b'].map((x) => ({[x]: x}));

console.log(result);

answered Jun 26 '18 at 15:12

Eddie

score 4 · Answer 3 · answered Jun 26 '18 at 15:14

4

whenever you return object from arrow functions you wrap them in paranthesis

['a', 'b'].map((x) => ({[x]:x}))

answered Jun 26 '18 at 15:14

ashish singh

3 Answers3