Java script key value pair to object

Question

I am new to javascript. I have an array of data in the format:

Toronto, Ontario: 95 
Markham, Ontario: 71

I want to convert it to an array of object:

Like this, to be consistent with other functions.

I tried:

reportData.fbcity = Object.keys(reportData.city).map((city) => {
    return {
        city: city,
        value: reportData.city[city]
    };
});

What I get is: {city: "Markham, Ontario": "value": 71}

Your desired format is not valid object, please update proper data — Code Maniac, May 29 '19 at 16:40
Yes, but I just want in that format in order to pass it to existing functions. — kevin, May 29 '19 at 16:41
Explain what you mean with the Array. That doesn't seem like an Array, it seems like an Object whose key is a city/country. — zero298, May 29 '19 at 16:42
@kevin - But since the quoted format is (probably) invalid (and your starting point is also vague), we don't know what you mean. There are at least two different ways to interpret what you've said you want, and at least two ways I can interpret what you say your starting point is. — T.J. Crowder, May 29 '19 at 16:42
@Alex - Well, unless there are in-scope variables with those names. ;-) (Thanks to shorthand properties in ES2015+) — T.J. Crowder, May 29 '19 at 16:43
@MaheerAli - Unless there's an in-scope variable called `Toronto`. ;-) — T.J. Crowder, May 29 '19 at 16:45
@T.J.Crowder These data are fetched from backend. No variable called Toronto... — kevin, May 29 '19 at 16:49
@kevin - Yes, that was a joke. Please update your question to show us your **actual** starting data. As I said above, it's unclear. I've guessed in my answer, but... — T.J. Crowder, May 29 '19 at 16:52

T.J. Crowder · Accepted Answer · 2019-05-29T17:00:43.450

Based on your updated question, I take it that you have this:

const start = ["Toronto, Ontario: 95", "Markham, Ontario: 71"];

and you want this:

result = [
    {"Toronto, Ontario": 95},
    {"Markham, Ontario": 71}
];

To do that, you need to split the number at the end of the string off, and then build objects with the two parts of the string. If you know there's only ever one :, then:

const result = start.map(str => {
    const [city, number] = str.split(":");
    return {
        [city]: +number
    };
});

Live Example:

const start = ["Toronto, Ontario: 95", "Markham, Ontario: 71"];
const result = start.map(str => {
    const [city, number] = str.split(":");
    return {
        [city]: +number
    };
});
console.log(result);

That uses destructuring to capture the two parts from split, then a computed property name to create a property with the city name, and + to coerce the number to number from string. (That's just one of your number-to-string options, see this answer for more options.)

@CodeManiac - Nope, there's really no justification and I'm going to remove it. :-) [The spec](https://tc39.github.io/ecma262/#sec-tonumber-applied-to-the-string-type) is quite clear about the whitespace being handled. — T.J. Crowder, May 29 '19 at 16:59

score 0 · Answer 2 · answered May 29 '19 at 16:49

0

reportData.fbcity = Object.keys(reportData.city).map((city) => {
    return {
        [city]: reportData.city[city]
    };
})

answered May 29 '19 at 16:49

Amit Chauhan

6,151
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Code Maniac · Answer 3 · 2019-05-29T16:54:29.490

0

You can use map and split

split with : and than build a object
+ is used to convert string to number

let data = ["Toronto, Ontario: 95", "Markham, Ontario: 71"];


let op = data.map(val=>{
  let [key,value] = val.split(':')
  return {[key]: +value}
})

console.log(op)

edited May 29 '19 at 16:54

answered May 29 '19 at 16:52

Code Maniac

37,143
5
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Java script key value pair to object

3 Answers3