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PHP PHP Arrays and Control Structures PHP Arrays Multidimensional Arrays

Posted by John Vicencio
John Vicencio
6,413 Points

Multidimentional array (questioning the question)

Source: https://teamtreehouse.com/library/php-arrays-and-control-structures/php-arrays/multidimensional-arrays

Question: in the code below, we have a simple array of contact names. We want to use the $contacts array to fill in the hardcoded list of names an email addresses. To hold the email as well as the name for each contact, we need a multidimensional array, meaning each person in the contact list will have their own array. The first step is to make each person their own single item ASSOCIATIVE array, using 'name' as the key for these internal arrays.

My solution didn't work, I think because the question isn't really clear.

Don't I do this?

$contacts = array(
  array('Alena Holligan', 'alena.holligan@teamtreehouse.com'),
  array('Dave McFarland', 'dave.mcfarland@teamtreehouse.com'),
  array('Treasure Porth', 'treasure.porth@teamtreehouse.com'),
  array('Andrew Chalkley', 'andrew.chalkley@teamtreehouse.com')
);


echo "<ul>\n";
//$contacts[0] will return 'Alena Holligan' in our simple array of names.
echo "<li>$contacts[0][0] : $contacts[0][1]</li>\n";
echo "<li>$contacts[1][0] : $contacts[1][1]</li>\n";
echo "<li>$contacts[2][0] : $contacts[2][1]</li>\n";
echo "<li>$contacts[3][0] : $contacts[3][2]</li>\n";
echo "</ul>\n";

But didn't work.

index.php 
<?php
//edit this array
$contacts = array('Alena Holligan', 'Dave McFarland', 'Treasure Porth', 'Andrew Chalkley');

echo "<ul>\n";
//$contacts[0] will return 'Alena Holligan' in our simple array of names.
echo "<li>Alena Holligan : alena.holligan@teamtreehouse.com</li>\n";
echo "<li>Dave McFarland : dave.mcfarland@teamtreehouse.com</li>\n";
echo "<li>Treasure Porth : treasure.porth@teamtreehouse.com</li>\n";
echo "<li>Andrew Chalkley : andrew.chalkley@teamtreehouse.com</li>\n";
echo "</ul>\n";
Joseph Arquímedes Collado Tineo
Joseph Arquímedes Collado Tineo
1,942 Points
Joseph Arquímedes Collado Tineo
Joseph Arquímedes Collado Tineo
1,942 Points

This is another option:

/*
 *@Author: Joseph A. Collado
 *@Date: 12/10/2018
 *@Challenge: Multidimentional array
 *
 */

<?php
//edit this array
$contacts[] = [
     'name'  => 'Alena Holligan',
     'email' => 'alena.holligan@teamtreehouse.com',
];

$contacts[] = [
     'name'  => 'Dave McFarland',
     'email' => 'dave.mcfarland@teamtreehouse.com',
];

$contacts[] = [
     'name'  => 'Treasure Porth',
     'email' => 'treasure.porth@teamtreehouse.com',
];

$contacts[] = [
     'name'  => 'Andrew Chalkley',
     'email' => 'andrew.chalkley@teamtreehouse.com',
];

echo "<ul>\n";
//$contacts[0] will return 'Alena Holligan' in our simple array of names.
echo "<li>" . $contacts[0]['name'] . ' : ' . $contacts[0]['email'] . "</li>\n";
echo "<li>" . $contacts[1]['name'] . ' : ' . $contacts[1]['email'] . "</li>\n";
echo "<li>" . $contacts[2]['name'] . ' : ' . $contacts[2]['email'] . "</li>\n";
echo "<li>" . $contacts[3]['name'] . ' : ' . $contacts[3]['email'] . "</li>\n";
echo "</ul>\n";

?>

19 Answers

David Soards
David Soards
18,368 Points
David Soards
David Soards
18,368 Points

the challenges in this course have not been clear at all. it's very frustrating

Emilze Eloy
Emilze Eloy
2,993 Points
Emilze Eloy
Emilze Eloy
2,993 Points 
<?php
//edit this array
$contacts = array(
      array(
     "name"=>"Alena Holligan",
     "email"=> 'alena.holligan@teamtreehouse.com'
  ),

   array(
     "name" => "Dave McFarland",
     "email" => "dave.mcfarland@teamtreehouse.com"
    ),

    array(
     "name"=> "Treasure Porth", 
     "email"=>'treasure.porth@teamtreehouse.com'
   ),

    array(
    "name" => "Andrew Chalkley",
    "email" => "andrew.chalkley@teamtreehouse.com"
  ) 
    );

echo "<ul>\n";
//$contacts[0] will return 'Alena Holligan' in our simple array of names.
echo "<li>". $contacts[0]['name'] . " : ". $contacts[0]['email'] ."</li>\n";
echo "<li>". $contacts[1]['name'] . " : ". $contacts[1]['email'] ."</li>\n";
echo "<li>". $contacts[2]['name'] . " : ". $contacts[2]['email'] ."</li>\n";
echo "<li>". $contacts[3]['name'] . " : ". $contacts[3]['email'] ."</li>\n"; 
echo "</ul>\n";

?>

Finally my code run correctly! :)

Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points

This is the third and last part of the challenge :)

Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points 
<?php
//edit this array
$contacts = array('Alena Holligan', 'Dave McFarland', 'Treasure Porth', 'Andrew Chalkley');
$contacts = array (
  array ( 
   'name' => 'Alena Holligan',
   'email' => 'alena.holligan@teamtreehouse.com'
  ),
  array (
   'name' => 'Dave McFarland',
     'email' => 'dave.mcfarland@teamtreehouse.com'
  ),
  array ( 
   'name' => 'Treasure Porth',
   'email' => 'treasure.porth@teamtreehouse.com'
  ),
  array (
   'name' => 'Andrew Chalkley',
    'email' => 'andrew.chalkley@teamtreehouse.com'
  ),
);
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points

This is the second part of the challenge! :)

A X
A X
12,842 Points

Yes you answered with code, but you didn't clarify on what this question was asking...as I also agree with John that the question isn't worded clearly at all in terms of what's an acceptable answer and what isn't. How did you arrive at this as the "correct" answer (aka the one TH will accept)?

This also doesn't work for part 1 of the assignment as the OP is asking about.

Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points 
$contacts = array (
   array (
    'name' => 'Alena Holligan',
    'email' => 'alena.holligan@teamtreehouse.com',
   ),
   array (
    'name' => 'Dave McFarland',
      'email' => 'dave.mcfarland@teamtreehouse.com',
   ),
   array (
    'name' => 'Treasure Porth',
    'email' => 'treasure.porth@teamtreehouse.com',
   ),
   array (
    'name' => 'Andrew Chalkley',
     'email' => 'andrew.chalkley@teamtreehouse.com',
   ),
 );
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points

Hi Eveliina Champagne, your code it looks fine, maybe the editor of treehouse doesn't works fine if we use the "[]" to create a multidimensional array. Try using and replace the first part of the third part for the code i left above of this comment! :)

Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points 
<?php
//edit this array
$contacts = array('Alena Holligan', 'Dave McFarland', 'Treasure Porth', 'Andrew Chalkley');
$contacts = array (
  array ( 'name' => 'Alena Holligan'),
  array ( 'name' => 'Dave McFarland'),
  array ( 'name' => 'Treasure Porth'),
  array ( 'name' => 'Andrew Chalkley'),
);
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points

This is the first part of the challenge!

John Vicencio
John Vicencio
6,413 Points

Thanks Juan. I figured it out.

A X
A X
12,842 Points

It doesn't work for part 1 of the challenge. Your code results in an error message: "I do not see the required output. You should not be modifying the output at this point."

Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points 
<?php
//edit this array
$contacts = array (
  array (
   'name' => 'Alena Holligan',
   'email' => 'alena.holligan@teamtreehouse.com',
  ),
  array (
   'name' => 'Dave McFarland',
     'email' => 'dave.mcfarland@teamtreehouse.com',
  ),
  array (
   'name' => 'Treasure Porth',
   'email' => 'treasure.porth@teamtreehouse.com',
  ),
  array (
   'name' => 'Andrew Chalkley',
    'email' => 'andrew.chalkley@teamtreehouse.com',
  ),
);
echo "<ul>\n";
//$contacts[0] will return 'Alena Holligan' in our simple array of names.
echo "<li>". $contacts [0] ['name'] . " : " . $contacts [0] ['email'] . "</li>\n";
echo "<li>". $contacts [1] ['name'] . " : " .  $contacts [1] ['email'] . "</li>\n";
echo "<li>". $contacts [2] ['name'] . " : " . $contacts [2] ['email'] . "</li>\n";
echo "<li>". $contacts [3] ['name'] . " : " . $contacts [3] ['email'] . "</li>\n";
echo "</ul>\n";
?>
John Vicencio
John Vicencio
6,413 Points

Thanks I figured it out. I was doing 3 steps ahead but had to do one step at the time.

hassan alzahrani
hassan alzahrani
3,623 Points
hassan alzahrani
hassan alzahrani
3,623 Points

BTW the space after the array name need to be removed or the treehouse excersize will gave an error even it is working o0

This

$contacts [0] ['name']

to this

$contacts[0]['name']
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points

Hi Hassan, it's works to me as I showed. But maybe you're right. !

Tibor Ruzinyi
Tibor Ruzinyi
17,968 Points
Tibor Ruzinyi
Tibor Ruzinyi
17,968 Points

Another option(but not working as an answer):

<?php
//edit this array
$contacts["Alena"]=[
"name" => "Alena Holligans",
"email" => "alena.holligan@teamtreehouse.com"
];

$contacts["Dave"]=[
"name" => "Dave McFarland",
"email" => "dave.mcfarland@teamtreehouse.com"
];

$contacts["Treasure"]=[
"name" => "Treasure Porth",
"email" => "treasure.porth@teamtreehouse.com"
];

$contacts["Andrew"]=[
"name" => "Andrew Chalkley",
"email" => "andrew.chalkley@teamtreehouse.com"
];





echo "<ul>\n";
//$contacts[0] will return 'Alena Holligan' in our simple array of names.
echo "<li>" . $contacts["Alena"]["name"]  . " : " . $contacts["Alena"]["email"] . "</li>\n";
echo "<li>" . $contacts["Dave"]["name"]  . " : " . $contacts["Dave"]["email"] . "</li>\n";
echo "<li>" . $contacts["Treasure"]["name"]  . " : " . $contacts["Treasure"]["email"] . "</li>\n";
echo "<li>" . $contacts["Andrew"]["name"]  . " : " . $contacts["Andrew"]["email"] . "</li>\n";
echo "</ul>\n";
A X
A X
12,842 Points

Tibor, I thought double quotes are treated differently than single quotes in php...I'm not sure if that will effect the array or not, but it's more a question than anything else...

Matthew Pray
Matthew Pray
7,137 Points
Matthew Pray
Matthew Pray
7,137 Points

Its sad that only treehouse version works.

John Vicencio
John Vicencio
6,413 Points
John Vicencio
John Vicencio
6,413 Points

Thanks! I was a bit ahead haha.

Nasir Atta
Nasir Atta
2,177 Points
Nasir Atta
Nasir Atta
2,177 Points

<?php //edit this array $contacts[] = array ( 'name' => 'Alena Holligan', 'email' => 'alena.holligan@teamtreehouse.com', ); $contacts[] =array ( 'name' => 'Dave McFarland', 'email' => 'dave.mcfarland@teamtreehouse.com', ); $contacts[] =array ( 'name' => 'Treasure Porth', 'email' => 'treasure.porth@teamtreehouse.com', ); $contacts[] = array ( 'name' => 'Andrew Chalkley', 'email' => 'andrew.chalkley@teamtreehouse.com', ); //echo var_dump($contacts);

echo "<ul>\n"; echo "<li>".$contacts[0]['name']." : ".$contacts[0]['email']."</li>\n"; echo "<li>".$contacts[1]['name']." : ".$contacts[1]['email']."</li>\n"; echo "<li>".$contacts[2]['name']." : ".$contacts[2]['email']."</li>\n"; echo "<li>".$contacts[3]['name']." : ".$contacts[3]['email']."</li>\n"; echo "</ul>\n";

?>

make sure that " : " have space from both side between the double commas.

robbertdekock
robbertdekock
13,390 Points
robbertdekock
robbertdekock
13,390 Points

Can anyone tell me if this is the 'cleanest' way to write the first 2 parts of this exercise?

<?php
$contacts = [
  ['name' => 'Alena Holligan', 'email' => 'alena.holligan@teamtreehouse.com'], 
  ['name' => 'Dave McFarland', 'email' => 'dave.mcfarland@teamtreehouse.com'], 
  ['name' => 'Treasure Porth', 'email' => 'treasure.porth@teamtreehouse.com'], 
  ['name' => 'Andrew Chalkley', 'email' => 'andrew.chalkley@teamtreehouse.com'],
];
?>
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points

Hi Robert, your code it's ok!, it's clean. Although, you can use the "array()" and the result will be the same. Here is a very useful link http://www.php-fig.org/psr/

robbertdekock
robbertdekock
13,390 Points

thnx!

Eveliina Champagne
Eveliina Champagne
11,554 Points
Eveliina Champagne
Eveliina Champagne
11,554 Points

Hi Juan,

sorry about the messy post. I'm new to posting here. Thank you for helping me! :)

Mahmoud Helal
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Mahmoud Helal
Full Stack JavaScript Techdegree Graduate 17,856 Points
Mahmoud Helal
.a{fill-rule:evenodd;}techdegree seal-36
Mahmoud Helal
Full Stack JavaScript Techdegree Graduate 17,856 Points

<?php $contacts = array('Alena Holligan', 'Dave McFarland', 'Treasure Porth', 'Andrew Chalkley');

$contacts = array ( array ( 'name' => 'Alena Holligan', 'email' => 'alena.holligan@teamtreehouse.com'), array ( 'name' => 'Dave McFarland','email' => 'dave.mcfarland@teamtreehouse.com'), array ( 'name' => 'Treasure Porth','email' => 'treasure.porth@teamtreehouse.com'), array ( 'name' => 'Andrew Chalkley','email' => 'andrew.chalkley@teamtreehouse.com') );

echo "<ul>\n"; echo "<li>" . $contacts[0]['name'], ' : ' . $contacts[0]['email'] . "</li>\n"; echo "<li>" . $contacts[1]['name'], ' : ' . $contacts[1]['email'] . "</li>\n"; echo "<li>" . $contacts[2]['name'], ' : ' . $contacts[2]['email'] . "</li>\n"; echo "<li>" . $contacts[3]['name'], ' : ' . $contacts[3]['email'] . "</li>\n"; echo "</ul>\n";

Tinashe Bvukumbwe
Tinashe Bvukumbwe
14,089 Points
Tinashe Bvukumbwe
Tinashe Bvukumbwe
14,089 Points

<?php //edit this array $contacts = array( array( "name"=>"Alena Holligan", "email"=> 'alena.holligan@teamtreehouse.com' ),

array( "name" => "Dave McFarland", "email" => "dave.mcfarland@teamtreehouse.com" ),

array(
 "name"=> "Treasure Porth", 
 "email"=>'treasure.porth@teamtreehouse.com'

),

array(
"name" => "Andrew Chalkley",
"email" => "andrew.chalkley@teamtreehouse.com"

) );

echo "<ul>\n"; //$contacts[0] will return 'Alena Holligan' in our simple array of names. echo "<li>". $contacts[0]['name'] . " : ". $contacts[0]['email'] ."</li>\n"; echo "<li>". $contacts[1]['name'] . " : ". $contacts[1]['email'] ."</li>\n"; echo "<li>". $contacts[2]['name'] . " : ". $contacts[2]['email'] ."</li>\n"; echo "<li>". $contacts[3]['name'] . " : ". $contacts[3]['email'] ."</li>\n"; echo "</ul>\n";

?>

Cesar De La Vega
Cesar De La Vega
13,900 Points
Cesar De La Vega
Cesar De La Vega
13,900 Points

This worked for me: 

<?php
//edit this array
$contacts = array(
   [
    'name' => 'Alena Holligan',
    'email' => 'alena.holligan@teamtreehouse.com',
   ],
   [
    'name' => 'Dave McFarland',
    'email' => 'dave.mcfarland@teamtreehouse.com',
   ],
   [
    'name' => 'Treasure Porth',
    'email' => 'treasure.porth@teamtreehouse.com',
   ],
   [
    'name' => 'Andrew Chalkley',
    'email' => 'andrew.chalkley@teamtreehouse.com',
   ],
);

echo "<ul>\n";
//$contacts[0] will return 'Alena Holligan' in our simple array of names.
echo "<li>Alena Holligan : alena.holligan@teamtreehouse.com</li>\n";
echo "<li>Dave McFarland : dave.mcfarland@teamtreehouse.com</li>\n";
echo "<li>Treasure Porth : treasure.porth@teamtreehouse.com</li>\n";
echo "<li>Andrew Chalkley : andrew.chalkley@teamtreehouse.com</li>\n";
echo "</ul>\n";
Christopher Hall
Christopher Hall
11,158 Points
Christopher Hall
Christopher Hall
11,158 Points

Here is my solution

<?php
//edit this array
$contacts = [
  ["name" => "Alena Holligan",
   "email" => "alena.holligan@teamtreehouse.com"], 
  ["name" => "Dave McFarland",
   "email" => "dave.mcfarland@teamtreehouse.com"], 
  ["name" => "Treasure Porth",
   "email" => "treasure.porth@teamtreehouse.com"], 
  ["name" => "Andrew Chalkley",
   "email" => "andrew.chalkley@teamtreehouse.com"]
  ];

echo "<ul>\n";
//$contacts[0] will return 'Alena Holligan' in our simple array of names.
echo "<li>Alena Holligan : alena.holligan@teamtreehouse.com</li>\n";
echo "<li>Dave McFarland : dave.mcfarland@teamtreehouse.com</li>\n";
echo "<li>Treasure Porth : treasure.porth@teamtreehouse.com</li>\n";
echo "<li>Andrew Chalkley : andrew.chalkley@teamtreehouse.com</li>\n";
echo "</ul>\n";
Eveliina Champagne
Eveliina Champagne
11,554 Points
Eveliina Champagne
Eveliina Champagne
11,554 Points

Hi,

I can't figure out what is wrong with this code. I'm on the third task of this challenge.

"Bummer! I do not see the use of the names from contacts array in the output. When calling the multidimensional array, you must first call the outer indexed array and then the inner associative array. Example: $array[#][STRING]"

<?php //edit this array $contacts [] = [ 'name' => 'Alena Holligan', 'email' => 'alena.holligan@teamtreehouse.com', ]; $contacts [] = [
'name' => 'Dave McFarland', 'email' => 'dave.mcfarland@teamtreehouse.com', ]; $contacts [] = [ 'name' => 'Treasure Porth', 'email' => 'treasure.porth@teamtreehouse.com', ]; $contacts [] = [ 'name' => 'Andrew Chalkley', 'email' => 'andrew.chalkley@teamtreehouse.com', ];

echo "<ul>\n"; //$contacts[0] will return 'Alena Holligan' in our simple array of names. echo "<li>". $contacts [0]['name'] . " : " . $contacts [0] ['email'] . "</li>\n"; echo "<li>". $contacts [1] ['name'] . " : " . $contacts [1] ['email'] . "</li>\n"; echo "<li>". $contacts [2] ['name'] . " : " . $contacts [2] ['email'] . "</li>\n"; echo "<li>". $contacts [3] ['name'] . " : " . $contacts [3] ['email'] . "</li>\n"; echo "</ul>\n";

Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points

Hi Eveliina, to see it better insert your code after writting... ```php so it'll appear with the black background! :)

Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points
Juan Ignacio Lambardi
Juan Ignacio Lambardi
3,943 Points

My pleasure!, and sorry for my english jaja

Eric C
Eric C
7,998 Points
Eric C
Eric C
7,998 Points

Juan can you elaborate on how to post code with the black background, I don't understand. Thanks in advance!