javascript - get top N values' keys of an Object -

demo object:

var foo = {a:1, b:2, c:3, d:4, e:5, f:6, g:7} 

wanted result: (get top 3 keys value)

{e:5, f:6, g:7} 

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explenation:

for given key/value basic object, how 3 top values, not values keys? keys anything. lets values integers.

performance should in mind.

you can extract properties array, sort array:

var foo = {a:1, b:2, c:3, d:4, e:5, f:6, g:7} var props = object.keys(foo).map(function(key) {   return { key: key, value: this[key] }; }, foo); props.sort(function(p1, p2) { return p2.value - p1.value; }); var topthree = props.slice(0, 3); 

if want result object, reduce one

var topthreeobj = props.slice(0, 3).reduce(function(obj, prop) {   obj[prop.key] = prop.value;   return obj; }, {});