


How to Modify Array Values in a PHP Foreach Loop: Reference or Key?
Dec 12, 2024 pm 05:29 PMModifying Array Values within a Foreach Loop
In PHP, it is possible to modify the current object being handled within a foreach loop. To do so, there are two primary approaches:
Using a Loop Variable with Array Key:
<?php foreach($questions as $key => $question){ $questions[$key]['answers'] = $answers_model->get_answers_by_question_id($question['question_id']); } ?>
Here, we iterate over the $questions array using a loop variable ($key) that represents the array index. By explicitly updating the $questions array at the corresponding index ($key), we effectively modify the original object.
Using a Reference:
<?php foreach($questions as &$question){ $question['answers'] = $answers_model->get_answers_by_question_id($question['question_id']); } ?>
In this case, we add an ampersand (&) before the loop variable ($question), which passes a reference to the object. By modifying the object through the reference, we directly update the object in the original $questions array.
Which Approach is Recommended?
While both approaches work, using a loop variable with array key is generally preferred. This is because it explicitly updates the original array, making it easier to track modifications for debugging or further processing.
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