Find an array that have only the not same object

Question

I've got an array:

var objArray = [
   { id: 0, name: ‘Object 0’, otherProp: ‘321’ },
   { id: 1, name: ‘O1’, otherProp: ‘648’ },
   { id: 2, name: ‘Another Object’, otherProp: ‘850’ },
   { id: 3, name: ‘Almost There’, otherProp: ‘046’ },
   { id: 4, name: ‘Last Obj’, otherProp: ‘984’ },
   { id: 0, name: ‘Object 0’, otherProp: ‘321’ }
];

here the id 0 add twice. I only want an array that not have the same objects.

expected output:

a = [
   { id: 0, name: ‘Object 0’, otherProp: ‘321’ },
   { id: 1, name: ‘O1’, otherProp: ‘648’ },
   { id: 2, name: ‘Another Object’, otherProp: ‘850’ },
   { id: 3, name: ‘Almost There’, otherProp: ‘046’ },
   { id: 4, name: ‘Last Obj’, otherProp: ‘984’ }]

How do I do this in JavaScript.

It's reasonable to create the array without doubles at the beginning. — Teemu, Jul 08 '19 at 11:08
What should happen if a duplicate ID is used? Don't insert the entry? Remove the previous entry? — VLAZ, Jul 08 '19 at 11:08
@Hasibul- By the way, I don't think your question is duplicate of question about an array of strings. What a community... — Alexander, Jul 08 '19 at 11:25
@Alexander yet it's trivial to adapt the code for arbitrary objects by comparing the property you want to consider unique (`id` in this case) instead of the item itself. We don't need a different question for each different case when it is all the same logic in the end. — VLAZ, Jul 08 '19 at 11:32

score 3 · Accepted Answer · answered Jul 08 '19 at 11:16

You could filter the array by looking for the id in a Set.

var array = [{ id: 0, name: 'Object 0', otherProp: '321' }, { id: 1, name: 'O1', otherProp: '648' }, { id: 2, name: 'Another Object', otherProp: '850' }, { id: 3, name: 'Almost There', otherProp: '046' }, { id: 4, name: 'Last Obj', otherProp: '984' }, { id: 0, name: 'Object 0', otherProp: '321' }],
    seen = new Set,
    result = array.filter(({ id }) => !seen.has(id) && seen.add(id));

console.log(result);

Thanks Nina Scholz :) it's working – Hasibul- Jul 08 '19 at 11:25 — Hasibul-, Jul 08 '19 at 11:25

Find an array that have only the not same object

1 Answers1