Dynamically create object from object array

Question

I have an array of objects that I need to turn into a new single object.

This is structure of array:

class QueryFilter {
 filterName;
 filterValue;
}
let filter1 = new QueryFilter();
filter1.filterName = "SpamScore";
filter1.filterValue = 5;
let filter2 = new QueryFilter();
filter2.filterName = "Pages";
filter2.filterValue = 50;
let filters = [filter1, filter2];

I need to turn filters into an object like this:

let newObj = {
 SpamScore: 5,
 Pages: 50
};

I have been trying with map and assign but I cant figure out the way I am supposed to do this. Does this require reflection of some type or is there a simple way?

• CertainPerformance: Can you post what you've tried?
• Guerrilla: I tried using assign and map and it didn't work so I don't see point of posting it as I am not sure if it is even those methods that I should be using.
• Tibrogargan: for(let filter of filters) { newObj[filter.filterName] = filter.filterValue }
• Tibrogargan: It's the same as object.property
• Tibrogargan: more fully: let newObj = {}; for(let f of filters) { newObj[f.filterName] = f.filterValue }

Answer 1

You can do it using Array#reduce:

filters.reduce((r, i) => {
 r[i.filterName] = i.filterValue;
 return r;
}, {});

The idea is to loop over the filters object, and in each iteration, assign the key-value to the result.

Answer 2

A simple reduce into an object would do it:

class QueryFilter {
}
let filter1 = new QueryFilter();
filter1.filterName = "SpamScore";
filter1.filterValue = 5;
let filter2 = new QueryFilter();
filter2.filterName = "Pages";
filter2.filterValue = 50;
let filters = [filter1, filter2];
console.log(
 filters.reduce((a, { filterName, filterValue }) => (
 Object.assign(a, { [filterName]: filterValue })
 ), {})
);

• Guerrilla: Ahh thanks. Funnily that method didn't come up when i was googling, thank you very much i will accept when timer allows

Answer 3

let newObj = {}
 
filters.forEach(x=> {
 newObj[x.filterName] = x.filterValue;
})
console.log(newObj)

Alternatively you can also use Array#forEach to achieve what you want