random_items()

string random_items(array|string basis, [int number])

Randomly selects number of items from a list of items or from all items in a question.

• basis
  A list of items (array or comma-separated) or a question ID
• number
  Number of items that should be drawn. If the second parameter is omitted, the items will be returned in a random order.

Note: As a rule, enabling item rotation directly in the question (Items' order → “Shuffle/rotate randomly”) is preferred over using the function random_items(). This function only provides real added value if the same random selection is needed again in a later question, or if not all of the items should be displayed.

It is assumed that questions AB01 and AB02 have the same items. The following PHP code shows the items in question AB01 in a random order – and the items in question AB02 in the same order.

$items = random_items('AB01');
question('AB01', $items);
question('AB02', $items);

Tip: If questions AB01 and AB02 should be asked on different pages, use registerVariable($items) to make the variable $items available for use on future pages.

In the following example, 3 items are randomly selected from items 1,2,3,4,9 and 9, and questions AB01 and AB02 are only shown with these items.

$items = random_items('1-4,8,9', 3);
question('AB01', $items);
question('AB02', $items);

The following PHP code shows 3 of the items from question AB01 at random.

$items = random_items('AB01', 3);
question('AB01', $items);

The same result can be also obtained, however, with a corresponding parameter in the command question().

question('AB01', 'random=3');