I have this nested objects
var obj = {
first:{
num:10
},
second: {
num:5
},
third: {
num: 15
}
}
console.log(obj);
so there could be a lot of nested objects inside and i need to get the object with highest num value inside which in this case is the third object.
So i should get as output
third: {
num: 15
}
I got stuck at the iteration
var arr = Object.keys( obj ).map(function ( key, index ) {
console.log(obj[key]);
});
console.log(arr);
as I mentioned in my comment above, what you mentioned as expected output is not really an object. however, you can use following snippet to find the key within ur main object which holds the highest num:
var running = Number.MIN_VALUE;
var ans = "";
Object.keys(object).forEach(key => {
if(object[key]["num"] > running) {
ans = key;
}
})
console.log(JSON.stringify(object[ans])); //outputs { num: 15 }
If you want the whole object back with the high value, I would use reduce
var obj = {
first:{
num:10
},
second: {
num:5
},
third: {
num: 15
}
}
const result = Object.entries(obj)
.reduce( (acc,[k,i]) => Object.values(acc)[0].num<i.num ? {[k]:i} : acc
, {zero:{num:0}})
console.log(result);No need for Object.keys (though that would be fine for getting an array of the object keys to check) or map, just a simple loop where you remember the object with the highest number you've seen so far:
let found = null;
// Loop through the keys of the object
for (const key in obj) {
// Get the value for this key
const entry = obj[key];
// If this is an own property of the object and either A) We
// don't have any "found" object yet or the one we do have has
// a lower `num` than this one, remember this one
if (Object.hasOwn(obj, key) && (!found || found.num < entry.num)) {
found = entry;
}
}
Live Example:
const obj = {
first:{
num:10
},
second: {
num:5
},
third: {
num: 15
}
};
let found = null;
for (const key in obj) {
const entry = obj[key];
if (Object.hasOwn(obj, key) && (!found || found.num < entry.num)) {
found = entry;
}
}
console.log(found);If you also need to remember the property name, just do that at the same time you assign to found.
That uses the newish Object.hasOwn function. If you need to support implementations that don't have it, use a curated polyfill or just:
if (!Object.hasOwn) {
Object.defineProperty(Object, "hasOwn", {
value: Function.prototype.call.bind(Object.prototype.hasOwnProperty),
writable: true,
configurable: true,
});
}