Getting error nested javascript filter property 'filter' of undefined

Question

var Posts = [
  {
    likes: ['5e5782c4f695d70b6e376c8c'],
    _id: '5e5782c4f695d70b6e376c7c',
    width: 473,
    height: 1000
  },
  {
    likes: ['5e5782c4f695d70b6e376c6d'],
    _id: '5e5782e7f695d70b6e376c82',
    width: 601,
    height: 1000
  }
];
const myId = '5e5782c4f695d70b6e376c8c';
const result = Posts.likes.filter(userId => userId.toString() !== myId.toString());
console.log("full", result);

Getting error TypeError: Cannot read property 'filter' of undefined may be cause of nested filter

Answer 1

The issue here is Posts is an array and thus Posts.likes returns undefined and thus you get this error. To fix this, you will simply need to apply the .filter() method on Posts array itself and then destructure the object for each item in the array and just get likes property from it and then match likes[0] with passed myId variable like:

 var Posts = [{ likes: ['5e5782c4f695d70b6e376c8c'], _id: '5e5782c4f695d70b6e376c7c', width: 473, height: 1000 }, { likes: ['5e5782c4f695d70b6e376c6d'], _id: '5e5782e7f695d70b6e376c82', width: 601, height: 1000 } ]; const myId = '5e5782c4f695d70b6e376c8c'; const result = Posts.filter(({likes}) => likes[0].== myId;toString()). console,log("full"; result);