How to loop an object and remove all functions from it

Question

Let's get right the issue, I need to remove all functions from a object to send via socket.io JSON! Let's say I have an object such as...

let myObject = {
    test1: "abc",
    test2: function() {
        console.log("This is a function");
    },
    test3: {
        test4: "another string",
        test5: function() {
            console.log("another function");
        },
        test6: 123
    }
}

and I need to convert it too

let myObject = {
    test1: "abc",
    test3: {
        test4: "another string",
        test6: 123
    }
}

I have tried many cod methods, all of which failed! I would post them but that would be wasting your valuable time. I'd love anyone who could fix this problem in a neat function manner. Yours Truly, Jacob Morris

PS Here is a piece of c**p attempt at doing this

 let myObject = { test1: "abc", test2: function() { console.log("This is a function"); }, test3: { test4: "another string", test5: function() { console.log("another function"); }, test6: 123 } } let i = []; function tsfr(ls) { let i = {}; for (let a in ls) { if (typeof(ls[a]) !== "function") { let d = ls[a]; if (typeof(d) == "object") { d = tsfr(d); } i[a] = d; } } return i; } i = tsfr(myObject); console.log(i) 

Answer 1

You can write your own recursive solution, but I think it is better to use JSON.stringify . By default stringify ignores functions and removes them from the result. In certain cases, it's second param, replacer function, can get handy for more advanced object manipulation.

 const removeFunctions = (obj) => { const stringified = JSON.stringify(obj); // We need to parse string back to object and return it const parsed = JSON.parse(stringified); return parsed; } const myObject = { test1: "abc", test2: function() { console.log("This is a function"); }, test3: { test4: "another string", test5: function() { console.log("another function"); }, test6: 123 } } console.log(removeFunctions(myObject)); 

(Or on codepen )

Please note that stringifying uses toString() method, and for some instances of custom classes can lead to a data loss. To prevent that, you'll need to write your own, recursive solution. It is probably going to be a lot more complicated.

Hope this helps, cheers!

EDIT: I just saw your attempt. It is a step in right direction, but it needs some more love. But I need to advise you against variable names like tsfr or ls . Code is much more readable if you use longer, more descriptive names.

EDIT2: As pointed by Andreas in the comments, you don't even need custom replacer as stringify ignores them and removes them by default.

Answer 2

You can use delete and recursively remove nested object properties it like this:

 let myObject = { test1: "abc", test2: function() { console.log("This is a function"); }, test3: { test4: "another string", test5: function() { console.log("another function"); }, test6: 123 } } const deleteFunctions = (obj) => { Object.keys(obj).forEach(k => { if (typeof obj[k] === "function") delete obj[k]; else if (typeof obj[k] === "object") deleteFunctions(obj[k]) }) } deleteFunctions(myObject) console.log(myObject) 

Answer 3

You could filter the key/value pairs by type checking and later map new object by checking the nested objects.

 const removeFn = object => Object.assign(...Object .entries(object).filter(([k, v]) => typeof v !== 'function') .map(([k, v]) => ({ [k]: v && typeof v === 'object' ? removeFn(v) : v })) ); var object = { test1: "abc", test2: function() { console.log("This is a function"); }, test3: { test4: "another string", test5: function() { console.log("another function"); }, test6: 123 } }; console.log(removeFn(object)); 

Answer 4

Just for fun, I'd do it this way. This is a revisitation of Douglas Crockford's DOM algorithms.

First, a recursive function ( visit() ) that visits an arbitrary object and applies an arbitrary function to each member:

function visit(obj, func)
{
  for (k in obj)
  {
    func(obj, k);

    if (typeof obj[k] === "object")
    {
      visit(obj[k], func);
    }
  }
}

This is a working example with a payload function that just outputs found functions to the console:

 var testdata = { "a": 1, "b": "hello", "c": [ 1, 2, 3 ], "d": (x) => 2 * x, "e": null, "f": { "x": 10, "y": { "z": "$$$", "zz": (x) => 0 } } }; function visit(obj, func) { for (k in obj) { func(obj, k); if (typeof obj[k] === "object") { visit(obj[k], func); } } } visit(testdata, (obj, k) => { if (typeof obj[k] === "function") { console.log(k + " is a function"); } }); 

As the code above shows, the payload function func is able to find all and only functions in the object.

All we need now is a function that removes the member, but this is very easy now:

(obj, k) => {
  if (typeof obj[k] === "function")
  {
    delete obj[k];
  }
}

By separating the visit from the payload you can reuse this in many ways and manipulate recursively objects for all kinds of necessities...

Answer 5

It will remove all the function from the above object

function removeFuncFromObj(obj) {
  Object.keys(obj).map((key) => {
    if (typeof obj[key] === "function") {
        delete obj[key];
    }
    if (typeof obj[key] === typeof {}) {
        removeFuncFromObj(obj[key]);
    }
  });
  return obj;
}
removeFuncFromObj(myObject);

[ https://jsbin.com/favikej/edit?js,console,output][1]