Combine data from array of objects

Question

I got this data structure and I am checking to see which properties are true, then I am adding the key for all the properties that are true to that object on a new property called combined

const data = [
 {
 keyword: 'banana',
 yellow: true,
 sweet: true
 },
 {
 keyword: 'pineapple',
 yellow: true,
 sweet: false
 },
 {
 keyword: 'apple',
 yellow: false,
 sweet: false
 },
]
const combined = [...data].reduce((acc, { keyword, ...rest}) => {
 const res = Object.entries(rest).reduce((total, [key, value]) => {
 if (value === true) total.push(key)
 return total
 }, [])
 acc.push(res)
 return acc
}, []).map(entry => ({ combined: entry.join(' ') }))
const output = data.map((entry, index) => ({
 ...entry,
 ...combined[index]
}))
console.log(output)

.as-console-wrapper { max-height: 100% !important; top: 0; }

It seems pretty straight forward but somehow this feels a bit convoluted

Answer 1

From a short review;

• Your own answer does read better
• map is the right approach
• I would go for filter instead of reduce (you only want 'true' values that are not keyword)
• I probably would have named total -> keys
• I prefer <verb><object> so combined -> addGroups
• If you dont use a falsy comparison, then you dont need to check for 'keyword'

const data = [
 {keyword: 'banana', yellow: true, sweet: true},
 {keyword: 'pineapple', yellow: true, sweet: false},
 {keyword: 'apple', yellow: false, sweet: false},
];
function addGroup(o){
 return {
 ...o,
 group: Object.keys(o).filter(key => o[key] === true).join(' ') 
 };
}
function addGroups(list){
 return list.map(o => addGroup(o));
}
console.log(addGroups(data))

.as-console-wrapper { max-height: 100% !important; top: 0; }

• Álvaro: Thank you for your answer, it works great. Any reason why you would no do something simpler like this: const addGroups = (arr) => arr.map(obj => ({ ...obj, group: Object.keys(obj).filter(key => obj[key] === true).join(' ') }))

Answer 2

I have improved it with this:

const data = [
 {
 keyword: 'banana',
 yellow: true,
 sweet: true
 },
 {
 keyword: 'pineapple',
 yellow: true,
 sweet: false
 },
 {
 keyword: 'apple',
 yellow: false,
 sweet: false
 },
]
const combined = [...data].map((entry) => {
 const group = Object.entries(entry).reduce((total, [key, value]) => {
 if (value && key !== 'keyword') total.push(key)
 return total
 }, []).join(' ')
 return {
 ...entry,
 group
 }
})
console.log(combined)

.as-console-wrapper { max-height: 100% !important; top: 0; }

Is this a better approach?