Any simpler and more efficient way of writing this code?

Question

I've noticed I've got quite a few repeated lines in my code.

$start = mktime(0, 0, 0, 3, 1, 2014);
$rate = 1 / 30;
$amount = number_format(floor((time() - $start) * $rate));

$id = array(
    array("42706686", "rebel2america"),
    array("100004055720670", "marquez.candace"),
    array("100000756492404", "vince.goode.3"),
    array("100007763585373", "laura.allen.75491"),
);

// 70% chance of red an 30% of green
$status = array(
    array("red", "no"),
    array("red", "no"),
    array("red", "no"),
    array("red", "no"),
    array("red", "no"),
    array("red", "no"),
    array("red", "no"),
    array("green", "yes"),
    array("green", "yes"),
    array("green", "yes")
);

$online = range(7, 21);

// create and assign a 'seed' value that changes 
// every $duration and assign to mt_srand
$duration = 5;
$mins = date('i', strtotime('now'));
$seed = $mins - ($mins % $duration);
mt_srand($seed);

// use mt_rand to build an 'order by'
// array that will change every $duration
$orderBy = array_map(function() {
    return mt_rand();
}, range(1, count($id)));

// sort $ids against $orderBy
array_multisort($orderBy, $id);

$orderBy = array_map(function() {
    return mt_rand();
}, range(1, count($status)));
array_multisort($orderBy, $status);

$orderBy = array_map(function() {
    return mt_rand();
}, range(1, count($online)));
array_multisort($orderBy, $online);

for($i = 0; $i < 10; $i++) {
    $results1 = array_pop($id);
    $results2 = array_pop($status);
    echo "                            <td>{$results1[0]}</td>\n";
    echo "                            <td>{$results1[1]}</td>\n";
    echo "                            <td><span class=\"{$results2[0]}\">{$results2[1]}</span></td>\n";
}

Answer 1

This part is duplicated:

$orderBy = array_map(function() {
    return mt_rand();
}, range(1, count($id)));
array_multisort($orderBy, $id);

You apply the same logic to $id, $status, $online.

To eliminate duplication, you can move this common logic to a function with one parameter:

function reorder(&$arr) {
    $orderBy = array_map(function() {
        return mt_rand();
    }, range(1, count($arr)));
    array_multisort($orderBy, $arr);
}
reorder($id);
reorder($status);
reorder($online);

Note that we pass the array by reference (&$arr), because array_multisort does the same, and modifies the content of the array anyway.

UPDATE

As other answers and comments have pointed out, you could also eliminate the magic numbers and duplication when creating the $status array, for example like this:

$color1 = array("red", "no");
$color2 = array("green", "yes");
$num_color1 = 7;
$num_color2 = 3;
$status = array_fill(0, $num_color1, $color1)
          + array_fill($num_color1, $num_color2, $color2);

Answer 2

Extract some constants:

replace

// 70% chance of red an 30% of green
$status = array(
    array("red", "no"),
    array("red", "no"),
    array("red", "no"),
    array("red", "no"),
    array("red", "no"),
    array("red", "no"),
    array("red", "no"),
    array("green", "yes"),
    array("green", "yes"),
    array("green", "yes")
);

by:

// 70% chance of red an 30% of green
$red = array("red", "no");
$green = array("green", "yes");
$status = array($red, $red, $red, $red, $red, $red, $red, $green, $green, $green);

Answer 3

I'm assuming you want your script to output a list of user ids, usernames, and online status. Each user has a 30% chance of being online and the list changes randomly every 5 minutes. If I'm wrong about any of that please correct me.

These lines of code don't affect the output.

$start = mktime(0, 0, 0, 3, 1, 2014);
$rate = 1 / 30;
$amount = number_format(floor((time() - $start) * $rate));

$online = range(7, 21);

$orderBy = array_map(function() {
    return mt_rand();
}, range(1, count($online)));
array_multisort($orderBy, $online);

• Your seed changes every five minutes, but loops every hour. This gives you just 12 possible seeds.
• For the online status, inside your loop generate a true/false value that has a certain probability of being true. This requires fewer lines of code and the maximum number of ids is not limited by the size of your status array.
• Use $i as an index to the array rather than poping elements.
• Don't print extra white space with your HTML, unless you have a specific reason for doing so.

The modified code:

// 30% chance of being online
$ONLINE_PROB = 0.3;

// create and assign a 'seed' value that changes 
// every $DURATION seconds and assign to mt_srand
$DURATION = 5*60;
mt_srand(floor(time()/$DURATION));

$id = array(
  array("42706686", "rebel2america"),
  array("100004055720670", "marquez.candace"),
  array("100000756492404", "vince.goode.3"),
  array("100007763585373", "laura.allen.75491"),
);
// randomly shuffle $id
$orderBy = array_map(function(){return mt_rand();},range(1,count($id)));
array_multisort($orderBy,$id);

for($i=0; $i<count($id); ++$i)
{
  echo "<td>{$id[$i][0]}</td><td>{$id[$i][1]}</td>";
  if(mt_rand()/mt_getrandmax() <= $ONLINE_PROB)
    echo "<td><span class=\"green\">yes</span></td>";
  else
    echo "<td><span class=\"red\">no</span></td>";
}