JavaScript-使用唯一属性标识对象

Question

I have managed to identify the highest number out of the count properties however I want to log the object associated with that number, ie log the object with the highest count number. How do I do this?

var objects = {

    object1: {username: 'mark', count: 3},
    object2: {username: 'dave', count: 5},
    object3: {username: 'lucy', count: 2},
};

var maxBap = Math.max.apply(Math,objects.map(function(o){return o.count;}));
console.log(maxBap);

Thanks

Answer 1

Instead of .map() , use .reduce() to get the desired target.

Here I'm returning the key of the result object. You could return the object directly if you wish.

 var objects = { object1: {username: 'mark', count: 3}, object2: {username: 'dave', count: 5}, object3: {username: 'lucy', count: 2}, }; var res = Object.keys(objects).reduce(function(resKey, key) { return objects[resKey].count > objects[key].count ? resKey : key }) document.querySelector("pre").textContent = res + ": " + JSON.stringify(objects[res], null, 4); 

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---

If objects was meant to be an Array, you can still use .reduce() , just without Object.keys() . This returns the objects directly, which was alluded to in the first solution.

 var objects = [ {username: 'mark', count: 3}, {username: 'dave', count: 5}, {username: 'lucy', count: 2}, ]; var res = objects.reduce(function(resObj, obj) { return resObj.count > obj.count ? resObj : obj }) document.querySelector("pre").textContent = JSON.stringify(res, null, 4); 

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Answer 2

You could use .reduce instead of .map .

const objects = [
  { username: 'mark', count: 3 },
  { username: 'dave', count: 5 },
  { username: 'lucy', count: 2 },
]

const max = objects.reduce((acc, obj) => (
  obj.count > acc.count ? obj : acc
))

console.log(max)

Answer 3

You can first find max of count and then find object with that count

 var objects = { object1: {username: 'mark', count: 3}, object2: {username: 'dave', count: 5}, object3: {username: 'lucy', count: 2}, }, result = null; var max = Math.max.apply(null, Object.keys(objects).map(e => {return objects[e].count})); for (var obj in objects) { if (objects[obj].count == max) result = objects[obj]; } console.log(result)