Sorting

sorting.js

a = [ {name:'robin', ranking:10 }, { name: 'sam', ranking: 40 }, { name: 'binu', ranking: 12 } ];

// Using function
function sort_by_key(array, key) {
    return array.sort(function(a, b) {
        var x = a[key]; var y = b[key];
        return ((x < y) ? -1 : ((x > y) ? 1 : 0));
    });
}

let average = (array) => array.reduce((a, b) => a + b) / array.length;

function avg(array, key) {
  return average(array.map(o => o[key]));
}


console.log(sort_by_key(a, 'ranking'));
console.log(avg(a, 'ranking'));