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PHP Build a Basic PHP Website (2018) Listing and Sorting Inventory Items Creating the Display Function

Alex Forseth
Alex Forseth
8,017 Points
Posted by Alex Forseth
Alex Forseth
8,017 Points

get_item_html function structure. How does it work?

How do the arguments (0:27 she says parameters but I am pretty sure they are arguments) $id and $item communicate with the associative array in the data.php file? How does the function know to assign $id to the catalog key and the $item to the interior array keys? When nothing inside of those arrays have been assigned a variable named $id or $item?

3 Answers

Stuart Wright
Stuart Wright
41,120 Points
Stuart Wright
Stuart Wright
41,120 Points

At around the 3:00 mark, she initiates the foreach loop:

<?php
foreach ($catalog as $id => $item)

This is PHP syntax for looping over an associative array ($catalog), and assigning the $id variable to the current key, and the $item variable to the current value. These can then be passed into the function.

Alex Forseth
Alex Forseth
8,017 Points
Alex Forseth
Alex Forseth
8,017 Points

so $id in the foreach loop passes itself to the $id in the function get_item_html below it?

mahdi askari
mahdi askari
15,174 Points
mahdi askari
mahdi askari
15,174 Points

cant I remove " $id => " if not then why?

Steven Snary
Steven Snary
17,540 Points
Steven Snary
Steven Snary
17,540 Points

For those that have noted that the $id s not used in the get_item_html() function - you are correct. In fact if you take the $id out from the parameter list in the function header and do not pass $id into the function call the code will still execute correctly.

$id is still required in the foreach expression since $catalog is an associative array and we want the foreach loop to separate the key and value from the $catalog array.

Maybe the key will be used in an upcoming lesson???

Steven Jackson
Steven Jackson
11,465 Points
Steven Jackson
Steven Jackson
11,465 Points

Thanks for the answer Steve! I'm adding a bit more because I was very confused by this at first. The $id parameter is not used in the function for some reason!

If you inspect the output string below the function you wont see the $id parameter being used like $item parameter. The $item parameter is used to pull key value pairs and shows up in the $output string. This is especially confusing because $id is used as a working variable in both foreach loops.

Test by removing the $id parameter from all three instances of our function (get_item_html($item/$catalog[$id])). After this, leave it as a working variable in both loops(foreach($catalog as $id => $item) and nothing breaks. I hope this helps!