Convert values in array of objects

Question

I have an array of objects with String values that I want to convert to Date, but I'm getting the following error:

Uncaught SyntaxError: Unexpected token :

How should I correctly do this conversion and return the same object structure?

array = [
    {
        end: "2017-05-18T09:00:00.000Z",
        start: "2017-05-18T06:00:00.000Z"
    },
    {
        end: "2017-05-19T07:00:00.000Z",
        start: "2017-05-19T06:00:00.000Z"
    },
    {
        end: "2017-05-20T08:00:00.000Z",
        start: "2017-05-20T07:00:00.000Z"
    }
]

result = array.map((element) => {
  {
    end: new Date(element.end),
    start: new Date(element.start),
  }
})

You can wrap the `{}` in parentheses.... `array.map(element) => ({ end, start})` otherwise you need to use `return` — Dom, May 16 '17 at 19:04

score 2 · Accepted Answer · edited May 23 '17 at 11:47

2

You either do:

result = array.map(element => ({
 end: new Date(element.end),
start: new Date(element.start),
}));

OR:

result = array.map(element => {
  return {
    end: new Date(element.end),
    start: new Date(element.start),
  };
})

May have a look at ECMAScript6 arrow function that returns an object

edited May 23 '17 at 11:47

Community

1
1

answered May 16 '17 at 19:04

Jonas Wilms

132,000
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gaganshera · Answer 2 · 2017-05-16T19:07:12.363

1

The error you're getting is because javascript here thinks { end: new Date(element.end), start: new Date(element.start), } is a code block. Change it to

result = array.map((element) => {
  return {
    end: new Date(element.end),
    start: new Date(element.start),
  }
})
console.log(result)

You're missing a return.

edited May 16 '17 at 19:07

answered May 16 '17 at 19:04

gaganshera

2,629
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score 1 · Answer 3 · answered May 16 '17 at 19:04

You could wrap an object in parenthesis ad return value.

let array = [{ end: "2017-05-18T09:00:00.000Z", start: "2017-05-18T06:00:00.000Z" }, { end: "2017-05-19T07:00:00.000Z", start: "2017-05-19T06:00:00.000Z" }, { end: "2017-05-20T08:00:00.000Z", start: "2017-05-20T07:00:00.000Z" }],
    result = array.map(element => ({
        end: new Date(element.end),
        start: new Date(element.start),
    }));

console.log(result);

score 0 · Answer 4 · edited May 16 '17 at 19:13

0

To return object using the arrow function you need extra brackets, like below:

results = array.map(el => ({ end: new Date(el.end), start: new Date(el.start) }) )

edited May 16 '17 at 19:13

Jonas Wilms

132,000
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149
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answered May 16 '17 at 19:06

achwilko

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7

Convert values in array of objects

4 Answers4