data.map(obj =>
{person_name: obj.user.name,
...obj})
Why above code failed?
my data look like this
[{user:{name:'hello'},age:1},{user:{name:'world'},age:1,{user:{name:'another_name'},age:1]
I want to 'pull' the obj.user.name out from the nested obj.
Try this:
data.map(obj => ({person_name: obj.user.name,...obj}))
The { at the beginning of the object was interpreted as the beginning of a block instead of an object.
You can read more about this on MDN
EDIT: As Pawel mentioned, using the spread operator with objects does not work with pure es6 you need to use a specific transform like in this proposal: https://github.com/tc39/proposal-object-rest-spread
You can't spread an object like this (throws SyntaxError at ....
I would write it using Object.assign:
data.map(obj => Object.assign({person_name: obj.user.name}, obj ));
With babel, you could use rest syntax (parameters) ... for getting the rest of the object and store name property directly.
var data = [{ user: { name: 'hello' }, age: 1 }, { user: { name: 'world' }, age: 1 }, { user: { name: 'another_name' }, age: 1 }];
console.log(data.map(({ user, ...obj }) => Object.assign(obj, { person_name: user.name })));.as-console-wrapper { max-height: 100% !important; top: 0; }
...obj count?function foo(...bar) {} which collects all arguments passed to foo. In your example, the callback will always only handle a single argument.First of all, if you want to create an object using an arrow function, you have to wrap the curly braces in parenthesis:
data.map(obj => ({ foo: 'bar' }));
Otherwise, JS thinks the curly braces are the function body, and you get a syntax error.
And secondly, you can't use the spread operator in object literals. You can only use it when calling a function, using the array literal or when destructuring.
You can use Array.prototype.map() and directly return the desired object:
const data = [{user: {name: 'hello'},age: 1}, {user: {name: 'world'},age: 1},{user: {name: 'another_name'},age: 1}];
const result = data.map(obj => {
return {
person_name: obj.user.name,
age: obj.age
};
});
console.log(result);.as-console-wrapper { max-height: 100% !important; top: 0; }
...objdoing? please add the wanted result as well....is a punctuator used in a number of different contexts (e.g. spread element, assignment rest element), it's not an operator.