Remove circular in object?

Question

Is it possible to remove the circular type that is inside an object?

let say

result = {
a : [Array],
b : [Object],
c : [Circular],
d : 'string'
e : {
  x : [Circular],
  y : {
    z : [Circular]
    }
}
}

to

result = {
    a : [Array],
    b : [Object],
    d : 'string'
    }

I wanted to filter out all the circular type within the objects.

Attempt 1:

Since the name for each object is also the same in the children object. I tried to delete it since most children circular object only points to the parents. (actually, I got confused on this part). Here is the code i tried to use.

let keys = Object.keys(obj)
keys.forEach(val => {
    if (obj[val] instanceof Object || obj[val] instanceof Array) {
        Object.values(obj[val]).filter(function (value, index, arr) {
            if (keys.indexOf(Object.keys(value)[index]) > 0) {
                delete obj[val][index]
            }
        })
    }
})

Take this function and adapt it to remove the properties: https://stackoverflow.com/a/14962496/5768908 — Gerardo Furtado, May 05 '19 at 10:06
i tried https://stackoverflow.com/a/40293777/9506054 and stackoverflow.com/a/14962496/5768908 and modified it to delete the circular type directly, but it just give me "Maximum call stack size exceeded" — Daniel Mana, May 05 '19 at 10:29

Jonas Wilms · Answer 1 · 2019-05-05T10:34:47.647

You could use a Set to filter out objects that are seen twice:

const noCirculars = v => {
  const set = new Set; 
  const noCirculars = v => {
    if(Array.isArray(noCirculars))
      return v.map(noCirculars);
    if(typeof v === "object" && v !== null) {
      if(set.has(v)) return undefined;
      set.add(v);

      return Object.fromEntries(Object.entries(v)
       .map(([k, v]) => ([k, noCirculars(v)])));
    }
    return v;
  };
  return noCirculars(v);
};

Remove circular in object?

1 Answers1