Why do we need the $id variable??????

Question

ok so look at the code below:

This:

function get_item_html($item) { $output = "<li><a href='#' /><img src='" . $item["img"] . "' alt='" . $item["title"] . "' />" . "<p>View Details</p>" . "</a></li>"; return $output; }

            foreach($catalog as $item) {
                echo get_item_html($item);
            }

looks absolutely the same as this:

function get_item_html($id, $item) { $output = "<li><a href='#' /><img src='" . $item["img"] . "' alt='" . $item["title"] . "' />" . "<p>View Details</p>" . "</a></li>"; return $output; }

            foreach($catalog as $id => $item) {
                echo get_item_html($id, $item);
            }

My question is why do you need to declare the variable $id and what does this do: foreach($catalog as $id => $item) {

}

I mean I don't understand the part $id => $item thanks!

Answer 1 · 2016-06-26T14:27:45Z

June 26, 2016 2:27pm

foreach($catalog as $id => $item) {

this iterates across the $catalog array. For each iteration, it assigns the associative array key to $id, and the value to $item. You use this syntax when the key matters. The following shows some examples:

<?php
$list = ['red', 'white', 'blue'];
foreach($list as $listItem){
    echo $listItem . " ";
}
echo "\n";
foreach($list as $key=>$listItem){
    echo "key:".$key." value:".$listItem . " ";
}
echo "\n";

//More Natural associative array
$nameToEyeColor = [
    "beth"=>"brown",
    "arnold"=>"generally bloodshot",
    34 => "this is a junk result"
];
foreach($nameToEyeColor as $key=>$value){
    echo "key:".$key." value:".$value . " ";
}
?>

outputs:

red white blue 
key:0 value:red key:1 value:white key:2 value:blue 
key:beth value:brown key:arnold value:generally bloodshot key:34 value:this is a junk result

Answer 2 · 2016-08-01T17:16:08Z

August 1, 2016 5:16pm

thanks a lot, this helped me a lot

Answer 3 · 2016-08-01T20:12:05Z

August 1, 2016 8:12pm

<?php

foreach ($catalog as $item){ echo nl2br($item . "\n");

} foreach ($catalog as $id=>$item){

    echo nl2br($id . "\n");

        foreach($item as $key=>$sub_item){

            echo nl2br($key . " = " .  $sub_item . "\n");
        }

    echo nl2br("\n");
}

echo nl2br($catalog[101]["title"] . "\n");

foreach ($catalog as $id=>$item){

 echo nl2br($catalog[$id]["title"] . "\n");

} ?>

Array Array Array Array Array Array Array Array Array Array Array Array 101 title = A Design Patterns: Elements of Reusable Object-Oriented Software img = img/media/design_patterns.jpg genre = Tech format = Paperback year = 1994 category = Books authors = Array publisher = Prentice Hall isbn = 978-0201633610

102 title = Clean Code: A Handbook of Agile Software Craftsmanship img = img/media/clean_code.jpg genre = Tech format = Ebook year = 2008 category = Books authors = Array publisher = Prentice Hall isbn = 978-0132350884

103 title = Refactoring: Improving the Design of Existing Code img = img/media/refactoring.jpg genre = Tech format = Hardcover year = 1999 category = Books authors = Array publisher = Addison-Wesley Professional isbn = 978-0201485677

104 title = The Clean Coder: A Code of Conduct for Professional Programmers img = img/media/clean_coder.jpg genre = Tech format = Audio year = 2011 category = Books authors = Array publisher = Prentice Hall isbn = 007-6092046981

201 title = Forrest Gump img = img/media/forest_gump.jpg genre = Drama format = DVD year = 1994 category = Movies director = Robert Zemeckis writers = Array stars = Array

202 title = Office Space img = img/media/office_space.jpg genre = Comedy format = Blu-ray year = 1999 category = Movies director = Mike Judge writers = Array stars = Array

203 title = The Lord of the Rings: The Fellowship of the Ring img = img/media/lotr.jpg genre = Drama format = Blu-ray year = 2001 category = Movies director = Peter Jackson writers = Array stars = Array

204 title = The Princess Bride img = img/media/princess_bride.jpg genre = Comedy format = DVD year = 1987 category = Movies director = Rob Reiner writers = Array stars = Array

301 title = Beethoven: Complete Symphonies img = img/media/beethoven.jpg genre = Clasical format = CD year = 2012 category = Music artist = Ludwig van Beethoven

302 title = Elvis Forever img = img/media/elvis_presley.jpg genre = Rock format = Vinyl year = 2015 category = Music artist = Elvis Presley

303 title = No Fences img = img/media/garth_brooks.jpg genre = Country format = Cassette year = 1990 category = Music artist = Garth Brooks

304 title = The Very Thought of You img = img/media/nat_king_cole.jpg genre = Jaz format = MP3 year = 2008 category = Music artist = Nat King Cole

A Design Patterns: Elements of Reusable Object-Oriented Software A Design Patterns: Elements of Reusable Object-Oriented Software Clean Code: A Handbook of Agile Software Craftsmanship Refactoring: Improving the Design of Existing Code The Clean Coder: A Code of Conduct for Professional Programmers Forrest Gump Office Space The Lord of the Rings: The Fellowship of the Ring The Princess Bride Beethoven: Complete Symphonies Elvis Forever No Fences The Very Thought of You

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Alexander Bogdanov

Alexander Bogdanov

Why do we need the $id variable??????

3 Answers

Simon Coates

Simon Coates

mustafa kahraman

mustafa kahraman

mustafa kahraman

mustafa kahraman