Arrays

Populate (fill) an index array with numbers

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
    [5] => 6
    [6] => 7
    [7] => 8
    [8] => 9
    [9] => Brian Lark
    [10] => 1
    [11] => 1.5
)

I=0 Val=1
I=1 Val=2
I=2 Val=3
I=3 Val=4
I=4 Val=5
I=5 Val=6
I=6 Val=7
I=7 Val=8
I=8 Val=9
I=9 Val=Brian Lark
I=10 Val=1
I=11 Val=1.5

Populate an index array with days of the week

Array
(
    [0] => Sun
    [1] => Mon
    [2] => Tue
    [3] => Wed
    [4] => Thu
    [5] => Fri
    [6] => Sat
)

Populate an associative array with book data

Array
(
    [title] => The Grapes of Wrath
    [author] => John Steinbeck
    [published] => 1939
)

Populate a multidimensional associative array with book data

Array
(
    [book1] => Array
        (
            [title] => The Grapes of Wrath
            [author] => John Steinbeck
            [published] => 1939
        )

    [book2] => Array
        (
            [title] => The Trial
            [author] => Franz Kafka
            [published] => 1925
        )

    [book3] => Array
        (
            [title] => The Hobbit
            [author] => J. R. Tolkien
            [published] => 1937
        )

    [book4] => Array
        (
            [title] => Tale of Two Cities
            [author] => Charles Dickens
            [published] => 1859
        )

)

var_dump is a print command for error checking. Prints false where print_r doesn't

Key=book1Val=array(3) {
  ["title"]=>
  string(19) "The Grapes of Wrath"
  ["author"]=>
  string(14) "John Steinbeck"
  ["published"]=>
  string(4) "1939"
}

Key=book2Val=array(3) {
  ["title"]=>
  string(9) "The Trial"
  ["author"]=>
  string(11) "Franz Kafka"
  ["published"]=>
  string(4) "1925"
}

Key=book3Val=array(3) {
  ["title"]=>
  string(10) "The Hobbit"
  ["author"]=>
  string(13) "J. R. Tolkien"
  ["published"]=>
  string(4) "1937"
}

Key=book4Val=array(3) {
  ["title"]=>
  string(18) "Tale of Two Cities"
  ["author"]=>
  string(15) "Charles Dickens"
  ["published"]=>
  string(4) "1859"
}

One
Two
bool(false)

if I forget the title of book3, it is The Hobbit
If I forget the author of book2, it is Franz Kafka

---

CODE FOLLOWS

<?php
include('includes/header.php');

// code
error_reporting(E_ALL);    // set error reporting to all

echo('<h1>Arrays</h1>');

echo('<p>Populate (fill) an index array with numbers </p>');

// populate array

$myarray = array();

for ($i = 1; $i < 10; $i++)
{
    $myarray[] = $i;
}

// you can allocate a new item in the array and append a value
// at the same time using empty square braces [] on the right hand
// side of an assignment statement

$myarray[] = "Brian Lark";
$myarray[] = 1;
$myarray[] = 1.5;

// show contents of array

//print_r($myarray);

echo('<pre>');
print_r($myarray);
echo('</pre>');

echo('<pre>');
for ($i = 0; $i < count($myarray); $i++)
{

    echo "I=", $i, " Val=", $myarray[$i], "<br/>";

}
echo('</pre>');

echo('<p>Populate an index array with days of the week </p>');

// populate array

$myarray = array("Sun", "Mon", "Tue","Wed", "Thu", "Fri", "Sat");

// show contents of array

echo('<pre>');
print_r($myarray);
echo('</pre>');

echo('<p>Populate an associative array with book data</p>');

// populate array

$myarray = array
(
    'title' => "The Grapes of Wrath",
    'author' => "John Steinbeck",
    'published' => "1939",
);

// show contents of array

echo('<pre>');
print_r($myarray);
echo('</pre>');


echo('<p>Populate a multidimensional associative array with book data</p>');

// populate array

$myarray = array
(
    'book1' => array
    (
        'title' => "The Grapes of Wrath",
        'author' => "John Steinbeck",
        'published' => "1939",
    ),
    'book2' =>  array
    (
        'title' => "The Trial",
        'author' => "Franz Kafka",
        'published' => "1925",
    ),
    'book3' =>  array
    (
        'title' => "The Hobbit",
        'author' => "J. R. Tolkien",
        'published' => "1937",
    ),
    'book4' =>  array
    (
        'title' => "Tale of Two Cities",
        'author' => "Charles Dickens",
        'published' => "1859",
    ),
);

// show contents of array

echo('<pre>');
print_r($myarray);
echo('</pre>');

echo("var_dump is a print command for error checking. Prints false where print_r doesn't");

echo('<pre>');
foreach($myarray as $k => $v)
{

    echo "Key=", $k, "Val=", var_dump($v), "<br />";

}
echo('</pre>');

// var_dump is prints False
$thing = FALSE;
echo('<pre>');
echo("One\n");
print_r($thing); // variable is always false when reached
echo("Two\n");
var_dump($thing);
echo('</pre>');

// arrays of arrays
echo('<pre>');
echo "if I forget the title of book3, it is ";
echo $myarray["book3"]["title"];
echo '<br />';
echo "If I forget the author of book2, it is ";
echo $myarray["book2"]["author"];
echo('</pre>');

//php documentation Null Coalescing operator
include('includes/footer.php');
?>


---