Answers for "how to get sum of a field in array ob object javascript"

javascript sum array of objects

arr = [{x:1}, {x:3}]

arr.reduce((accumulator, current) => accumulator + current.x, 0);

js get sum of array of objects

const getSumByKey = (arr, key) => {
  return arr.reduce((accumulator, current) => accumulator + Number(current[key]), 0)
}

arr = [{x:1}, {x:3}]
getSumByKey(arr, 'x') // returns 4

Sum of Array of Objects in JavaScript

class fruitCollection extends Array {
    sum(key) {
        return this.reduce((a, b) => a + (b[key] || 0), 0);
    }
}
const fruit = new fruitCollection(...[
    {  description: 'orange', Amount: 50},
    {  description: 'orange', Amount: 50},
    {  description: 'apple', Amount: 75},
    {  description: 'kiwi', Amount: 35},
    {  description: 'watermelon', Amount: 25 },]);

console.log(fruit.sum('Amount'));