Random within a Random

Question

Guys, I have this code here:

<?php
// Define um array com alguns sites:
$site[] = 'google.com';
$site[] = 'facebook.com';


// Escolhe um valor aleatório (respeitando o total de sites)
$destino = rand(0, (count($site) - 1));

// Redireciona o usuario:
header("Location: " . $site[$destino]);
?>

He currently randomly chooses between the two links and opens one of them. But I wanted a simple change, and I don’t know how to do it exactly because I don’t understand much of it. I wanted the second option to have two options. But what do you mean? I wanted something like this?

<?php
// Define um array com alguns sites:
$site[] = 'google.com';
$site[] = 'youtube.com'  ouuu  'facebook.com';


// Escolhe um valor aleatório (respeitando o total de sites)
$destino = rand(0, (count($site) - 1));

// Redireciona o usuario:
header("Location: " . $site[$destino]);
?>

So, an Andom inside an Andom. Someone could help me with this?

Answer 1

What you want is to draw an element from the list with different weights. There is an explanation for this in the question below and it is not worth replicating here:

• Random draw, but with different odds

In PHP, a possible implementation would be:

$urls = [
    'url A' => 50,
    'url B' => 25,
    'url C' => 25
];

$x = rand(0, 100);

foreach ($urls as $url => $probability) {
    $x -= $probability;

    if ($x <= 0) {
        echo $url;
        break;
    }
}

Where URL A has a 50% chance of being drawn, URL B has a 25% chance and URL C has a 25% chance of being drawn. You can change it $urls freely, provided that the sum of the probabilities is always 100, for obvious reasons.

Answer 2

<?php
$sites = array("siteprincipal");
$site_ind = array("siteindependente1.com", "siteindependente2.com", "siteindependente3.com", "siteindependente4.com");
$sites[1] = $site_ind;
$destino = rand(0, count($sites)-1);
if(is_array($sites[$destino])){
    $destinoind = rand(0, count($sites[$destino])-1);
    header("Location:". $sites[$destino][$destinoind]);
}else{
    header("Location:".$sites[$destino]);
}
?>