reduce in array of objects code example

Example 1: javascript reduce sum

arrSum = function(arr){  return arr.reduce(function(a,b){    return a + b  }, 0);}

Example 2: javascript reduce array of objects

var objs = [
  {name: "Peter", age: 35},
  {name: "John", age: 27},
  {name: "Jake", age: 28}
];

objs.reduce(function(accumulator, currentValue) {
  return accumulator + currentValue.age;
}, 0); // 35 + 27 + 28 = 90

Example 3: javascript reduce

var array = [36, 25, 6, 15];

array.reduce(function(accumulator, currentValue) {
  return accumulator + currentValue;
}, 0); // 36 + 25 + 6 + 15 = 82

Example 4: creating array of objects usinng reduce js

const posts = [
    {id: 1, category: "frontend", title: "All About That Sass"},
    {id: 2, category: "backend", title: "Beam me up, Scotty: Apache Beam tips"},
    {id: 3, category: "frontend", title: "Sanitizing HTML: Going antibactirial on XSS attacks"}
];

const categoryPosts = posts.reduce((acc, post) => {
    let {id, category} = post;
    return {...acc, [category]: [...(acc[category] || []), id]};
}, {});

Example 5: reduce method in javascript array of bjects

var arr = [{x:1}, {x:2}, {x:4}];
arr.reduce(function (acc, obj) { return acc + obj.x; }, 0); // 7
console.log(arr);

Example 6: .reduce mdn

arr.reduce(callback( accumulator, currentValue[, index[, array]] )[, initialValue])

Tags:

Python Example

Recent Posts