How to turn object with array into array?

Question

I'm trying to turn the values of an array inside an object to a normal array.

Right now I'm doing something like this in my AJAX success function:

var obj = data
 
console.log(obj)
var array = Object.keys(obj)
 .map(function(key) {
 return obj[key];
 });
console.log(array)

This is what I get in my console:

{jaar: Array(2)}
 jaar: Array(2)
 0: YEAR(Scan): "2020"
 [[Prototype]]: Object
 1: YEAR(Scan): "2021"
 [[Prototype]]: Object
 length: 2
 [[Prototype]]: Array(0)
 [[Prototype]]: Object

I want to have something simply as this

["2020", "2021"]

How can I achieve this and what am I doing wrong right now?

console.log(obj) at the start gives this output in the console:

jaar: Array(2)
0: {YEAR(Scan): '2020'}
1: {YEAR(Scan): '2021'}
length: 2
[[Prototype]]: Array(0)
[[Prototype]]: Object ```

• transGLUKator: Can you show what does your obj variable contain?
• Justinas: Have you tried Object.values(obj.jaar)? developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…
• fdomn-m: Would be useful to know what you are starting with...
• Swauters: Hey @Justinas I've just tried what you've said. It seems to be giving me a correct array, problem now is the values inside are undefined.
• Tushar Shahi: Please show what console.log(obj) says at the start

Answer 1

If you have a plain object like const obj = { x: 10, y: 20 } and you want to have an array of its values, you can simply use Object.values(obj) that will return you [10, 20].

Seems like your object has more complex structure.

If you know for sure, any value of your object is a value or array, like const obj2 = { x: 10, y: [20, 30, 40], z: [50, 60]} you can flatten it.

Object.values(obj2).flat() will return you [10, 20, 30, 40, 50, 60].

For more complex structures you need to have more complex handlers.

Answer 2

jaar is already an array of objects. You can simply use .map() and get the respective property value from each array element.

let ans =jaar.map(x => x['YEAR(Scan)']);

Answer 3

Other answer provides the must succinct code (using .map) - to make the the smallest change to your existing code, change:

You can read the YEAR(Scan) property like so:

return obj[key]["YEAR(Scan)"];

Updated code:

var obj = 
 [ 
 { "YEAR(Scan)":"2020" },
 { "YEAR(Scan)":"2021" }
 ]
 
console.log(obj)
var array = Object.keys(obj)
 .map(function(key) {
 return obj[key]["YEAR(Scan)"];
 });
console.log(array)

• Swauters: I'm still getting undefined when I console.log
• Swauters: I don't believe YEAR(Scan) is an actual string value, it's greyed out in the console.
• fdomn-m: Hard to tell, I had to recreate the object from the console.log as it wasn't provided. Added the console.log(obj) (and to the snippet above) and it looks the same to me in the browser console 0: {YEAR(Scan): '2020' } - "year(scan)" is greyed and not in quotes. Note, it is not a string, you use ["string"] to access variables with invalid variable names var YEAR(Scan)=2020 would give an error. Perhaps you could add: console.log(JSON.stringify(obj)) so the original obj can be recreated faithfully.
• Swauters: {jaar: Array(2)}jaar: (2) [{...}, {...}][[Prototype]]: Object chart.js:567 (2) [{...}, {...}]