JavaScript/object.html at master · vishal-vaish/JavaScript · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>

</body>
</html>
<script>
    let obj={
        fullname: {
            firstName:"Vishal",
            lastname:"Vaish",
        },
        address:{
            city:"Lucknow",
            state:"Uttar Pradesh",
        },
        age: 25,
    };
    let objCopy=obj;
   // objCopy.age=23;
    //if you change in copy than the change is reflect in original


    const objCopyByvalue=Object.create(obj);
    objCopyByvalue.age=26;

    console.log("obj age",obj.age);
    console.log("objcopy age", objCopyByvalue.age);

    //object.create creates a shallow copy
    // objCopyByvalue.address.city="kanpur";
    // console.log("obj address",obj.address.city);
    // console.log("objcopy address", objCopyByvalue.address.city);
    //shallow copy means copy by value for a stage one
    //it is not good for nested object

    //2. JSON.stringify()
    //convert the object to string
    // const deepcopy=JSON.parse(JSON.stringify(obj));
    // deepcopy.address.city="kanpur";
    // console.log("obj address",obj.address.city);
    // console.log("objcopy address", deepcopy.address.city);
    // //convert the string to object again use JSON.parse

    //3. Spread operator
    // ...
    //it create an object
    const spreadobject={...obj};
    console.log(spreadobject);


</script>