CODEWITHSUNDEEP
phparraysrandom
Douglas Cottrell
Douglas Cottrell

Reputation: 281

php select multiple random keys from array

I have been trying to select random items from an array without repeating the same item.

Sample Array

$images=array();
$images[]=array('img'=>'bands.jpg','cat'=>'bands.php');
$images[]=array('img'=>'cake.jpg','cat'=>'cakes.php');
$images[]=array('img'=>'catering.jpg','cat'=>'catering.php');
$images[]=array('img'=>'dj.jpg','cat'=>'djs.php');
$images[]=array('img'=>'dress.jpg','cat'=>'dress_attire.php');
$images[]=array('img'=>'limos.jpg','cat'=>'limos_transportaion.php');
$images[]=array('img'=>'photography.jpg','cat'=>'photography.php');
$images[]=array('img'=>'venues.jpg','cat'=>'venues.php');
$images[]=array('img'=>'wedding_planer.jpg','cat'=>'planning.php');

I have tried the following but for some reason it will not work correctly. It is only collecting the first items in the array to the count rendered. // $adDisplay is a number between 1-9

$rand = array_rand($images, $adDisplay);
foreach($rand as $key => $value){
    echo'<a href="'.$images[$key]['cat'].'"><img src="img/banners/'.$images[$key]['img'].'" border="0" alt="" /></a>';
}

Upvotes: 3

Views: 1783

Answers (6)

Eligos
Eligos

Reputation: 1132

Alternative suggestion:

$images = array();
$images[]=array('img'=>'bands.jpg','cat'=>'bands.php');
$images[]=array('img'=>'cake.jpg','cat'=>'cakes.php');
$images[]=array('img'=>'catering.jpg','cat'=>'catering.php');
$images[]=array('img'=>'dj.jpg','cat'=>'djs.php');
$images[]=array('img'=>'dress.jpg','cat'=>'dress_attire.php');
$images[]=array('img'=>'limos.jpg','cat'=>'limos_transportaion.php');
$images[]=array('img'=>'photography.jpg','cat'=>'photography.php');
$images[]=array('img'=>'venues.jpg','cat'=>'venues.php');
$images[]=array('img'=>'wedding_planer.jpg','cat'=>'planning.php');

for ($i = 0; $i < $adDisplay AND sizeof($images) > 1; $i++) {
    $k = array_rand(0, sizeof($images)-1);
    $image = $images[$k];
    unset($images[$k];
    sort($images);
    echo '<a href="' . htmlspecialchars($image['cat']) . '">'
         . '<img src="img/banners/'
         . htmlspecialchars($image['img']) . ' border="0" alt="" />'
         . '</a>';
}

So, picks a random key, removes that record from the array, displays it and re-sorts the array for the next go-round. Continues until enough have been displayed or it runs out of records.

Upvotes: 0

Alan
Alan

Reputation: 1

You can simply use array_rand and store latest key on variable or somewhere

If random_key == last_used_key then Random_key+1

Not harder than that :-)

Upvotes: 0

Emil Aspman
Emil Aspman

Reputation: 1016

Use shuffle if you want your array in random order:

shuffle($images);

foreach($images as $img) {
    echo($img['cat']);
}

Or use array_rand to get a random key:

$key = array_rand($images);

echo($images[$key]['cat']);

Upvotes: 0

Nick
Nick

Reputation: 111

Many ways of doing this, I'd probably shuffle and then slice the array:

$images = array();
$images[]=array('img'=>'bands.jpg','cat'=>'bands.php');
$images[]=array('img'=>'cake.jpg','cat'=>'cakes.php');
$images[]=array('img'=>'catering.jpg','cat'=>'catering.php');
$images[]=array('img'=>'dj.jpg','cat'=>'djs.php');
$images[]=array('img'=>'dress.jpg','cat'=>'dress_attire.php');
$images[]=array('img'=>'limos.jpg','cat'=>'limos_transportaion.php');
$images[]=array('img'=>'photography.jpg','cat'=>'photography.php');
$images[]=array('img'=>'venues.jpg','cat'=>'venues.php');
$images[]=array('img'=>'wedding_planer.jpg','cat'=>'planning.php');

shuffle($images);

$adDisplay = 5;

foreach( array_slice($images,0,$adDisplay) as $image){
    echo '<a href="' . htmlspecialchars($image['cat']) . '">'
         . '<img src="img/banners/'
         . htmlspecialchars($image['img']) . ' border="0" alt="" />'
         . '</a>';
}

Upvotes: 3

Kevin Kenyon
Kevin Kenyon

Reputation: 43

The key will be the index, value will be the random variable, thus use value instead of key as the index into your images array. Cheers.

Upvotes: 0

Explosion Pills
Explosion Pills

Reputation: 191729

array_rand returns the random keys as values. You actually want to use $images[$value]['cat']. Also keep in mind that array_rand does not return an array if one item is requested; you must handle that specially.

Upvotes: 0

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