reduce method to sum by category object javascript code example

Example 1: reduce object to array javascript

var arr = [{x:1},{x:2},{x:4}];

arr.reduce(function (a, b) {
  return {x: a.x + b.x}; // returns object with property x
})

// ES6
arr.reduce((a, b) => ({x: a.x + b.x}));

// -> {x: 7}

Example 2: javascript, reduce

const myReduce = myArray.reduce((acc, item) => {
	acc += item
})