Filter on array of objects, and foreach over second array for conditions

Question

I've hit a snag after a few hours -- wondered if a fresh minded developer can just review the below, the code is simplied to show the problem.

I am filtering a property value on an array of objects, and cross referencing that property with an array which has matching keys, and boolean values to control if it should be factored into the filter.

However my result is returning all 3 objects, despite the console.log seeming to evaluate correctly. Any ideas?

Many thanks...

var data = [{
    "id": 1,
    "status": "new",
  },
  {
    "id": 2,
    "status": "rejected",
  },
  {
    "id": 3,
    "status": "changed",
  }
];

var filter = {
  "new": true,
  "rejected": false,
  "changed": true
}

var result = data.filter(function(item) {
  var arr = [];

  Object.keys(filter).forEach(function(key) {
    if (item.status === key && filter[key] === true) {

      console.log('---')
      console.log('item.status', item.status)
      console.log('key', key)
      console.log('filter[key]', filter[key])
      console.log('---')

      arr.push(item);
    }
  });

  return arr;
});

Mark · Accepted Answer · 2018-06-24 22:14:34Z

3

You're making this a bit more complicated than you need to. The function passed to filter() should return a boolean — you're returning an array.

You can simply filter with the lookup on the filter array, which will either return false or undefined, in which case you filter it out, or true, in which case you keep it..

var data = [{
    "id": 1,
    "status": "new",
  },
  {
    "id": 2,
    "status": "rejected",
  },
  {
    "id": 3,
    "status": "changed",
  }
];

var filter = {
  "new": true,
  "rejected": false,
  "changed": true
}

var result = data.filter(item => filter[item.status])

console.log(result)

answered Jun 24, 2018 at 22:14

Mark

92.6k8 gold badges116 silver badges156 bronze badges

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

Comments

CertainPerformance · Accepted Answer · 2018-06-24 22:14:33Z

2

You filter by returning something truthy or falsey directly, not by returning anything more specific (like an object). You can simplify your code to a one-liner:

var data=[{"id":1,"status":"new",},{"id":2,"status":"rejected",},{"id":3,"status":"changed",}]
var filter = {
  "new": true,
  "rejected": false,
  "changed": true
}

var result = data.filter((item) => filter[item.status])
console.log(result);

answered Jun 24, 2018 at 22:14

CertainPerformance

373k55 gold badges354 silver badges359 bronze badges

Comments

Tholle · Accepted Answer · 2018-06-24 22:14:40Z

2

filter will create a new array with every item that returned a truthy value. This should work:

var result = data.filter(function(item) {
  return filter[item.status];
});

answered Jun 24, 2018 at 22:14

Tholle

113k22 gold badges209 silver badges198 bronze badges

Collectives™ on Stack Overflow

Filter on array of objects, and foreach over second array for conditions

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related