Random URL redirect from array

Question

/** * Political Animals * contentscript.js is loaded on each page(s) listed in manifest.json * This plugin replaces all the images on the website of news sites with pic

Answer 1

Generate a "random" key and use window.location.href to redirect the user. Others have posted the same approach, though with less explanation. I'm giving my best to let you actually understand what happens here.

Note that most of this code is comments. It looks longer than it actually is.

var acceptedWebsites = ['http://www.cnn.com/', 'www.nytimes.com', 'www.latimes.com', 'http://www.washingtonpost.com/', 'http://www.nbcnews.com/', 'http://www.foxnews.com/'];

// This function returns a random key for an array
function randomKey(arr) {
    // Math.random() returns a number between 0 and 0.99999...
    // If you multiply this value with the length of an array, you get a
    // random floating point number between 0 and that length.
    // Use Math.floor() to round it down to the next integer
    return Math.floor(Math.random() * arr.length);
}

// Select a random website from the array
var key = randomKey(acceptedWebsites);
var newLocation = acceptedWebsites[key];

// Redirect the user
window.location.href = newLocation;