deep copy nested object

  Write a code to deep copy nested object.

Code:

var obj ={

    name:"sangram",

    address:{

        city:"mumbai",

        state:"maharashtra",

        pin:"4000**",

office:null,

        contactNo:{

            "landline":"***67-554569",

            "mobile":"**78456729",

        }

    }

}

function deepCopy(obj){

    var deepCopied={}

    for(let key in obj){

        if (obj[key] !== null || typeof obj[key] !== "object") {

            deepCopied[key] = obj[key]

        }else{

            deepCopied[key] = deepCopy(obj[key])

        }

    }

    return deepCopied

}

let x = deepCopy(obj);

console.log("Final Output:",x)

Output:

Final Output: {

  name: 'sangram',

  address: {

    city: 'mumbai',

    state: 'maharashtra',

    pin: '4000**',

office:null,

    contactNo: { landline: '***67-554569', mobile: '**78456729' }

  }

}

Note:deepcopy & deepclone term are used interchangeably in interviews & discussion.

Compare boolean with empty array

Guess output of following program

console.log(Boolean([]));   // true

console.log(![]);           // false

console.log(false == []);   // true

console.log(false == ![]);  // true

Output:

        true

        false

        true

        true

Explation in 3rd line

        console.log(false == []); // false == "" then 0 == 0 then true

In 4t line

        console.log(false == ![]);  //  false == ! true then false == false then true