CODEWITHSUNDEEP
phparrays
user-44651
user-44651

Reputation: 4124

Randomly pick one item from an array and then delete

I have an array of values.

 array =  ["A", "B", "C"];

I want to randomly select an item, do something with it, then remove it from the array. Go back and get another item, etc.. etc..

So that I get:

$item = "B";
array = ["A","C"]; 
$item = "C";
array = ["A"]; 
$item = "A";
array =[];

I know Ruby has a array.delete_at() function which would work great if i was using Ruby. Is there a function similar to that in just generic PHP?

Upvotes: 0

Views: 722

Answers (2)

AbraCadaver
AbraCadaver

Reputation: 78994

Randomize with shuffle() and then pop one off the end, or shift off of the beginning with array_shift(), doesn't matter:

shuffle($array);  // you only need to do this once
$item = array_pop($array);

Similar to the Ruby you show would be to get a random key and use it to get the value, then use it to unset() that element:

$item = $array[$key=array_rand($array)];
unset($array[$key]);

Upvotes: 3

Grawer
Grawer

Reputation: 121

There are two possible answers:

If you don't care about order of elements that will be left in the array, for example you will pick all elements anyway:

$array =  ["A", "B", "C"];

shuffle($array);
while (!empty($array)) {
    $randomElement = array_pop($array);
    var_dump($randomElement);
}

If you don't want to pick all element, only few. You can remove just elements that you pick, leaving other in the same order:

 $array =  ["A", "B", "C"];

 while (!empty($array)) {
     $randomKey = array_rand($array);
     $randomElement = $array[$randomKey];
     unset($array[$randomKey]);
     var_dump($randomElement);
 }

Upvotes: 1

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