ES6+ Spread Operator
Spread operator '...' will take data from an array and send it as comma seperated values
Example1:

    const nums = [1, 2, 3, 4];
    console.log(...nums);
Example2:

    //declaration of the function
    function calc(x,y,z) {
        return x * y + z;
    }

    // declaration of the array
    const nums = [3, 5, 8];

    //assignment of the values of the array as the operators in the function
    console.log(cal(...nums);)
in JavaScript, assigning an object to another object creates a twin.
a change in the new object will affect the original object.
When declaring an object

    let person1 = {             
        name = 'Guy',
        age = 46
    }
and assigning it to a now object

    let person2 = person1;
when we modify a child in the new object

    person2.name = 'Ofek';
the original object will be affected too

    console.log(person1.name)   //will return 'Ofek'
Instead, Spread Operator can be used to create a duplicate of the object, that will have its own life

    let person2 = {...person1};      //assigning old boject to a new object
    person2.name = 'Ofek'            //modifying a child object in the new object
    console.log(person1.name);       //will return 'Guy' 
    //Does not affect the original object
Although this will make a duplicate of the object, a child object will still be a linked clone

    let grandpa = {
        name: 'Yosef',
        age: 80,
        father: {
            name: 'Meni',
            age: 50
            kid: {
                name: 'Snir',
                age: 17
            } 
        }
    };
And changing a value of a child object in one object

    let grandpa2 = {...grandpa1
    };
    grandpa2.name = 'Avraham';
    grandpa2.father.name = 'Itzhak';
    grandpa2.father.kid.name = 'Rave';
will affect the other

    grandpa1:
        name: "Yosef"
        age: 80,
        father: 
            name: "Itzhak",
            age: 50
            kid:
                name: "Rave"    
                age: 17
The best way to create a full duplicate of object with child objects is with

JSON.stringify


    grandpa2 = JSON.parse(JSON.stringify(grandpa1));
This way each duplicate will have its own life , including its decendents
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