Ndtyjky

I have an array structured like this and I'm trying to get a copy of it (to modify and use for React setState()). In Python I can use copy.deepcopy() but I can't find an easy way to do this in JavaScript.

notes=[

        {

          contents: "Hello World 1",

          function: console.log,

          children: [

            {

              contents: "Hello World A",

              function: console.log,

              children: 

            },

          ]

        },

        {

          contents: "Hello World 2",

          function: console.log,

          children: 

        }

      ]

I found this article and similar solutions on stackoverflow, but none of them work for me.
https://medium.com/@Farzad_YZ/3-ways-to-clone-objects-in-javascript-f752d148054d
Two solutions are only a shallow copy, and JSON.parse doesn't work on functions.

I'd like to have a function that can deep copy any array or object containing any arbitrary structure of nested JavaScript datatypes.

I'd rather not reinvent the wheel writing a complex recursive function to traverse and clone everything, is there any existing solution?

I'm answering my own question with the solution I found. Someone posted this in the comment section of the article I linked and it seems to work

notes=[

        {

          contents: "Hello World 1",

          function: console.log,

          children: [

            {

              contents: "Hello World A",

              function: console.log,

              children: 

            },

          ]

        },

        {

          contents: "Hello World 2",

          function: console.log,

          children: 

        }

      ]



function deepCopy(src) {

  let target = Array.isArray(src) ?  : {};

  for (let key in src) {

    let v = src[key];

    if (v) {

      if (typeof v === "object") {

        target[key] = deepCopy(v);

      } else {

        target[key] = v;

      }

    } else {

      target[key] = v;

    }

  }



  return target;

}

shortest way if you can not find better answer

var note2 = JSON.parse(JSON.stringify(notes))

but it didnt copy functions

so check

function iterationCopy(src) {

  let target = {};

  for (let prop in src) {

    if (src.hasOwnProperty(prop)) {

      target[prop] = src[prop];

    }

  }

  return target;

}

const source = {a:1, b:2, c:3};

const target = iterationCopy(source);

console.log(target); // {a:1, b:2, c:3}

// Check if clones it and not changing it

source.a = 'a';

console.log(source.a); // 'a'

console.log(target.a); // 1

and

function bestCopyEver(src) {

  return Object.assign({}, src);

}

const source = {a:1, b:2, c:3};

const target = bestCopyEver(source);

console.log(target); // {a:1, b:2, c:3}

// Check if clones it and not changing it

source.a = 'a';

console.log(source.a); // 'a'

console.log(target.a); // 1

from Deep copy using iteration

you should use for loop iterate it and judge item type, when it is object type, use recursion. the function like:

function copy(obj1, obj2) {

  var obj2=obj2||{}; 

  for(var name in obj1) {

    if(typeof obj1[name] === "object") { 

      obj2[name]= (obj1[name].constructor===Array)?:{}; 

      copy(obj1[name],obj2[name]);

     } else {

      obj2[name]=obj1[name]; 

   }

 }

  return obj2; 

}