How to use Reduce in javascript?

The reduce() method is used to apply a function to each element in the array to reduce the array to a single value.

Example:

const ages = [33,12,20,16,5,54,21,44,23,55,45,90];

let ageSum = 0;

for(let i=0; i < ages.length; i++){
     ageSum += ages[i];
  }
//result
console.log(ageSum);
// 418

The method:

const ageSum = ages.reduce((total,age) => total + age ,0);
//result
console.log(ageSum);
// 418