test

gistfile1.txt

//use script not recommended in es6 modules
export {average, sort_by_ranking_desc};

let items = [],max_test_items=10;

for ( let i=0;i<max_test_items;i++) {
    items[i] = { name: "foo", ranking: Math.random() };
}

let sort_by_ranking_desc = (a, b) => (b.ranking-a.ranking );

let average = (arrobj) => {
    return arrobj.reduce((a, b) => ({ranking: a.ranking + b.ranking})).ranking/arrobj.length;
} ;


//display
console.log(average(items));
console.log(items.sort(sort_by_ranking_desc));