How to write a Node.js code to continuously keep watch on website/s?

I have a JSON array input like this in which I have multiple URL's which I have to keep watch on.

var urlList = {
    link: [{
        url: "www.google.com",
        status: ""
    }, {
        url: "www.w3schools.com",
        status: ""
    }]
}; 

When a particular website from this JSON array is down, I should get notified on console.

via rohit7