Destructuring

var {color, position} = {
    color: "blue",
    name: "hemant",
    state: "USA",
    position: "UI Dev"
};

console.log(color, position); // blue UI Dev

Use Case 1

function generateObj(){
    return {
        color: "blue",
        name: "hemant",
        state: "USA",
        position: "UI Dev"
    };
}

var {name, state} = generateObj();
console.log(name, state); // hemant USA

rename variable name

function generateObj(){
    return {
        color: "blue",
        name: "Paa",
        state: "India",
        position: "UI Dev"
    };
}

var {name:firstName, state: location} = generateObj();
console.log(firstName, location); // Paa India

Use Case 2

var [first,,,,last] = [1,2,3,4,5];

console.log(first, last); // 1 5

Use Case 3

var friends = [
    {
        name: "Hemant",
        location: "Hyd",
        status: "Cool",
        email: "[e-mail]"
    },
    {
        name: "Vinay",
        location: "USA",
        status: "NOO",
        email: "[e-mail]"
    }
];

friends.forEach(function({name, email}){
    console.log(name +", "+ email);
});

// output
Hemant, [e-mail]
Vinay, [e-mail]