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Darinel Cigarroa
Asked: 2022-09-27 14:52:24 +0800 CST 2022-09-27 14:52:24 +0800 CST

How to add elements of an array of objects with js using reduce?

  • 772

I have the following array of objects I want to add the ages of all the people:

let personas = [
    {id: 1, name:'Darinel', edad: 24, lastName:'Cigarroa', ciudad: 'CDMX'},
    {id: 2, name:'Darwin', edad: 24, lastName:'De jesus', ciudad: 'CDMX'},
    {id: 3, name:'Vera', edad: 24, lastName:'Dominguez', ciudad: 'CDMX'},
    {id: 4, name:'Emiliano', edad: 24, lastName:'Silva', ciudad: 'CDMX'},
    {id: 5, name:'Derky', edad: 24, lastName:'Wilner', ciudad: 'CDMX'},
    {id: 6, name:'Juan', edad: 24, lastName:'De La Cruz', ciudad: 'CDMX'},
];

I am trying this way but without any result:

let reduce = personas.reduce((acumulador, actual) => acumulador.edad + actual.edad);
console.log(reduce)
javascript

2 Answers

  1. Best Answer

    You are almost correct. The accumulator in this case will be an integer, not an object (it has no age property) and you must give it a start value (in this case 0)

    let personas = [
    {id: 1, name:'Darinel', edad: 24, lastName:'Cigarroa', ciudad: 'CDMX'},
    {id: 2, name:'Darwin', edad: 24, lastName:'De jesus', ciudad: 'CDMX'},
    {id: 3, name:'Vera', edad: 24, lastName:'Dominguez', ciudad: 'CDMX'},
    {id: 4, name:'Emiliano', edad: 24, lastName:'Silva', ciudad: 'CDMX'},
    {id: 5, name:'Derky', edad: 24, lastName:'Wilner', ciudad: 'CDMX'},
    {id: 6, name:'Juan', edad: 24, lastName:'De La Cruz', ciudad: 'CDMX'},
];


let reduce = personas.reduce((acumulador, actual) => acumulador + actual.edad, 0);
console.log(reduce)

    • 3

  2. Looping through the object with the forEach() method and accumulating into variables.

     let personas = [
  {id: 1, name:'Darinel', edad: 24, lastName:'Cigarroa', ciudad: 'CDMX'},
  {id: 2, name:'Darwin', edad: 24, lastName:'De jesus', ciudad: 'CDMX'},
  {id: 3, name:'Vera', edad: 24, lastName:'Dominguez', ciudad: 'CDMX'},
  {id: 4, name:'Emiliano', edad: 24, lastName:'Silva', ciudad: 'CDMX'},
  {id: 5, name:'Derky', edad: 24, lastName:'Wilner', ciudad: 'CDMX'},
  {id: 6, name:'Juan', edad: 24, lastName:'De La Cruz', ciudad: 'CDMX'}
];

var sumaedad    = 0;
var nropersonas = 0;

personas.forEach( function(persona){
         sumaedad    += persona.edad;
         nropersonas += 1;
 })
console.log( ` Cant.Persona: ${nropersonas} la suma de edades acumula: ${sumaedad} `);
    • 0