Getting undefined result when trying to loop and filtering array

Question

I am currently working with objects and arrays in nodejs in conjuction with filters. I am currenlty facing difficulty in figuring out how to properly traverse an object and filter for the desired results. Instead I am getting undefined. I have an object users and I am wanting to filter for each user configuration that has active === true and then ultimately display every users configuration with that filter in the final result. What is the right/best way to approach this? Should I use map?

Current Result:

undefined

Desired Result:

[
    {
        email: '[email protected]',
        active: true
    },
    {
        email: '[email protected]',
        active: true
    },
    {
        email: '[email protected]',
        active: true
    }
]

Code:

const users = [
    {
      name: 'User1',
      configuration: [ 
          {
            email: '[email protected]',
            active: true
          },
          {
            email: '[email protected]',
            active: false
          }
      ],
    },
    {
      name: 'User2',
      configuration: [ 
          {
            email: '[email protected]',
            active: true
          },
          {
            email: '[email protected]',
            active: true
          }
      ],
    },
];

const result = users.forEach(user => user.configuration.filter( x => {

    let {
        active
    } = x;

    return active === true;
}));

console.log(result);

cmgchess · Accepted Answer · 2022-02-27 10:31:57Z

2

you can use flatMap for this. forEach always returns undefined. usually if you want to return some array use map but since filter also returns an array you need to flat it to get your desired result hence flatMap

const users = [{name: 'User1',configuration: [ {email: '[email protected]',active: true},{email: '[email protected]',active: false}],},{name: 'User2',configuration: [ {email: '[email protected]',active: true},{email: '[email protected]',active: true}],},];

const result = users.flatMap(user => user.configuration.filter( x => x.active===true));

console.log(result);

answered Feb 27, 2022 at 10:31

cmgchess

10.3k42 gold badges55 silver badges70 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Youssouf Oumar · Accepted Answer · 2022-02-27 10:36:24Z

0

You could use two forEach like so:

const users = [
  {
    name: "User1",
    configuration: [
      {
        email: "[email protected]",
        active: true
      },
      {
        email: "[email protected]",
        active: false
      }
    ]
  },
  {
    name: "User2",
    configuration: [
      {
        email: "[email protected]",
        active: true
      },
      {
        email: "[email protected]",
        active: true
      }
    ]
  }
];
let result =[];
users.forEach((user) =>
  user.configuration.forEach((x) => {
  if (x.active) {
    result.push(x)
  }
})
);

console.log(result);

answered Feb 27, 2022 at 10:36

Youssouf Oumar

47.5k16 gold badges109 silver badges108 bronze badges

Collectives™ on Stack Overflow

Getting undefined result when trying to loop and filtering array

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related