[
{ name: 'Joe', scores: [1, 2, 3] },
{ name: 'Jane', scores: [1, 2, 3] },
{ name: 'John', scores: [1, 2, 3] }
]
how do I make a function that sorts the elements first by the sum in scores and later by name?
Using Array#sort, sort the array by the sum of scores, or name as fallback (using String#localeCompare)
const arr = [ { name: 'Joe', scores: [1] }, { name: 'Jane', scores: [1, 2] }, { name: 'John', scores: [1, 2] } ];
const sum = (arr = []) => arr.reduce((total, num) => total + num, 0);
const sorted = arr.sort((a, b) =>
sum(b.scores) - sum(a.scores) || a.name.localeCompare(b.name)
);
console.log(sorted);You could take a Map for all sums and the object as key without mutating data.
const
data = [{ name: 'Joe', scores: [1, 2, 3] }, { name: 'Jane', scores: [1, 4, 3] }, { name: 'John', scores: [1, 2, 1] }],
add = (a, b) => a + b,
sums = new Map(data.map(o => [o, o.scores.reduce(add, 0)]));
data.sort((a, b) => sums.get(b) - sums.get(a) || a.name.localeCompare(b.name));
console.log(data);.as-console-wrapper { max-height: 100% !important; top: 0; }The lodash package could be handy
const lodash = require('lodash')
const list = [
{ name: 'Joe', scores: [1, 2, 4] },
{ name: 'Jane', scores: [1, 2, 3] },
{ name: 'John', scores: [1, 2, 4] }
]
const listWithSum = list.map(item => {
return {
...item,
sum: lodash.sum(item.scores)
}
})
const sortedList = lodash.orderBy(listWithSum, ['score', 'name'], ['desc', 'desc'])
console.log(sortedList)