Using JavaScript what's the quickest way to recursively remove properties and values from an object?

Question

I need to find the fastest way to remove all $meta properties and their values from an object, for example:

{
  \"part_one\": {
    \"name\": \"         


        

Answer 1

As @floor commented above:

JSON.parse(JSON.stringify(obj, (k,v) => (k === '$meta')? undefined : v))

Answer 2

Here is a function that takes either a string or an array of strings to remove recursively (based on Joseph's answer):

// removes all propsToRemove (passed as an array or string), drilling down up to maxLevel times
// will modify the input and return it
du.removeAllPropsFromObj = function(obj, propsToRemove, maxLevel) {
    if (typeof maxLevel !== "number") maxLevel = 10
    for (var prop in obj) {
        if (typeof propsToRemove === "string" && prop === propsToRemove)
            delete obj[prop];
        else if (propsToRemove.indexOf(prop) >= 0)      // it must be an array
            delete obj[prop];
        else if (typeof obj[prop] === "object" && maxLevel>0)
            du.removeAllPropsFromObj(obj[prop], propsToRemove, maxLevel-1);
    }
    return obj
}

Answer 3

// Helper function
function removeProps(obj,keys){
  if(obj instanceof Array){
    obj.forEach(function(item){
      removeProps(item,keys)
    });
  }
  else if(typeof obj === 'object'){
    Object.getOwnPropertyNames(obj).forEach(function(key){
      if(keys.indexOf(key) !== -1)delete obj[key];
      else removeProps(obj[key],keys);
    });
  }
}
// The object we want to iterate
var obj = {
  "part_one": {
    "name": "My Name",
    "something": "123",
    "$meta": {
      "test": "test123"
    }
  },
  "part_two": [
    {
      "name": "name",
      "dob": "dob",
      "$meta": {
        "something": "else",
        "and": "more"
      }
    },
    {
      "name": "name",
      "dob": "dob"
    }
  ],
  "$meta": {
    "one": 1,
    "two": 2
  }
};
// Utilize the utility
removeProps(obj,['$meta']);
// Show the result
document.body.innerHTML = '<pre>' + JSON.stringify(obj,null,4) + '</pre>';

Answer 4

(Apologies, I do not yet have enough reputation points to comment directly.)

Just FYI, typeof null === 'object', so in the removeMeta() example offered by @joseph-marikle, the function will recurse on a null value.

Read more here: why is typeof null "object"?

Answer 5

A simple self-calling function can do it.

function removeMeta(obj) {
  for(prop in obj) {
    if (prop === '$meta')
      delete obj[prop];
    else if (typeof obj[prop] === 'object')
      removeMeta(obj[prop]);
  }
}

var myObj = {
  "part_one": {
    "name": "My Name",
    "something": "123",
    "$meta": {
      "test": "test123"
    }
  },
  "part_two": [
    {
      "name": "name",
      "dob": "dob",
      "$meta": {
        "something": "else",
        "and": "more"
      }
    },
    {
      "name": "name",
      "dob": "dob"
    }
  ],
  "$meta": {
    "one": 1,
    "two": 2
  }
}

function removeMeta(obj) {
  for(prop in obj) {
    if (prop === '$meta')
      delete obj[prop];
    else if (typeof obj[prop] === 'object')
      removeMeta(obj[prop]);
  }
}

removeMeta(myObj);

console.log(myObj);

Answer 6

I created this functions when any key is in any level in the object using the reference function of @Joseph Marikle

const _ = require("lodash");
const isObject = obj => obj != null && obj.constructor.name === "Object";
const removeAttrDeep = (obj, key) => {
    for (prop in obj) {
      if (prop === key) delete obj[prop];
      else if (_.isArray(obj[prop])) {
        obj[prop] = obj[prop].filter(k => {
          return !_.isEmpty(removeAttrDeep(k, key));
        });
     } else if (isObject(obj[prop])) removeAttrDeep(obj[prop], key);
    }
    return obj;
 };

EXAMPLE:

 const _obj = {
       a: "b", b: "e", c: { a: "a", b: "b", c: "c"},
       d: [ { a: "3" }, { b: ["2", "3"] }]};
 console.log(removeAttrDeep(_obj, "b"));