Reduce the array to the object with highest age:

const arr = [{"name":"John","age":15},{"name":"Max","age":17},{"name":"Tom","age":11}]

const result = arr.reduce((acc, o) => !acc || o.age > acc.age ? o : acc, null)

console.log(result)

I'm using null as the default value for the Array.reduce() to prevent an error if the array is empty. However, you can check for an empty array beforehand as well:

const findMaxAge = arr => arr.length 
  ? arr.reduce((acc, o) => o.age > acc.age ? o : acc)
  : null

const arr = [{"name":"John","age":15},{"name":"Max","age":17},{"name":"Tom","age":11}]

console.log(findMaxAge(arr))

console.log(findMaxAge([]))

You can sort by age first, then the object with the highest age value will be at the start of the list:

const a = [
  {name: "John", age: 15},
  {name: "Max", age: 17},
  {name: "Tom", age: 11},
]

const sortedByAge = a.sort((a,b) => b.age - a.age);

const highestAge = sortedByAge[0];

console.log(highestAge);

hope this code helping you

const a = [{name: 'John', age: 15},
       {name: 'Max', age: 17},
       {name: 'Tom', age: 11},];
const result = a.reduce((p, c) => p.age > c.age ? p : c);
console.log(result);