Creating an Array¶

To create an array, just say - amazingly - array and set it to a variable:

<?php
    $pet1 = 'Chew Barka';
    $pet2 = 'Spark Pug';
    $pet3 = 'Pico de Gato';

    $pets = array();
?>

This looks just like a function, and basically it is. But instead of returning a string or number, it returns an array, which is like a box that you can put strings, numbers or other things into. Right now the box is empty.

To put things in the box, just pass them as arguments when creating the array:

<!-- index.php -->
<!-- ... -->

<?php
    $pet1 = 'Chew Barka';
    $pet2 = 'Spark Pug';
    $pet3 = 'Pico de Gato';

    $pets = array($pet1, $pet2, $pet3);
?>

There are now 3 strings inside our array waiting to see what we’ll do with them. Like any box full of stuff, we can either pull out one specific item or pull out every item one at a time. In our case, we want to loop through each pet and print its name inside our HTML markup.

Looping over an Array¶

In PHP, we loop over arrays using the all-important foreach statement. Let’s remove the repeated code we have now and create just 1 loop that will print all 3:

<!-- index.php -->
<!-- ... -->

<?php
    $pet1 = 'Chew Barka';
    $pet2 = 'Spark Pug';
    $pet3 = 'Pico de Gato';

    $pets = array($pet1, $pet2, $pet3);
?>

<div class="container">
    <div class="row">
        <?php
            foreach ($pets as $pet) {
                echo '<div class="col-lg-4">';
                echo '<h2>';
                echo $pet;
                echo '</h2>';
                echo '</div>';
            }
        ?>
    </div>

    <!-- ... -->
</div>

Refresh and success! Congratulations on creating and looping over your first array. This is one of the most common and important skills in PHP.

One unfortunate side effect is that we’re now printing out the static HTML tags like the div and the h2 via PHP. This is totally fine, but it looks a bit uglier. There is a way to make this all look a lot prettier, which we’ll talk about in the next episode of this series.

foreach isn’t a function, it’s what’s called a “language construct”. That basically means that it looks and works like a function, but has its own, special syntax. There aren’t many of these language constructs and I’ll point them out along the way.

To loop, we say $pets as $pet. The first variable is the array we’re looping over and the second is a new variable name, which PHP sets to the value of each item in the array as we loop. Since our array has 3 strings in it, foreach executes the lines between { and } 3 times and $pet is set to a different string each time.

If I change $pet to something else, that’s fine, as long as I change it inside the curly braces as well:

foreach ($pets as $cutePet) {
    echo '<div class="col-lg-4">';
    echo '<h2>';
    echo $cutePet;
    echo '</h2>';
    echo '</div>';
}

Also notice that our new code contains the first 2 lines of PHP that don’t end in a semicolon. This is pretty common: either you’re writing a normal line that ends in a semi-colon or you’re using a language construct that has an opening { and a closing }. We’ll see another example of that later with the if statement.

Accessing Specific Items in an Array¶

In addition to looping over each item in an array, you can also just access one specific item. First, let’s see how an array looks under the surface by using a handy debugging function called var_dump. var_dump, like echo, prints things to the screen. But var_dump is better for debugging because it prints things out in a really descriptive way. If you have a variable and want to know everything about it, var_dump is your new best friend:

<!-- index.php -->
<!-- ... -->

<?php
    $pet1 = 'Chew Barka';
    $pet2 = 'Spark Pug';
    $pet3 = 'Pico de Gato';

    $pets = array($pet1, $pet2, $pet3);
    var_dump($pets);
?>

When we refresh, we see the word “array” that tells us what type of value our variable is. Afterwards, we see our 3 strings next to the number 0, 1 and 2:

array(3) {
  [0] =>
  string(10) "Chew Barka"
  [1] =>
  string(9) "Spark Pug"
  [2] =>
  string(12) "Pico de Gato"
}

<!-- index.php -->
<!-- ... -->

<?php
    $pet1 = 'Chew Barka';
    $pet2 = 'Spark Pug';
    $pet3 = 'Pico de Gato';

    $pets = array($pet1, $pet2, $pet3);

    echo $pets[0];
    echo $pets[2];
?>

// ...
$pets = array($pet1, $pet2, $pet3);

echo $pets[3];

Putting other Stuff into an Array¶

We’ve only put strings into our array so far, but we can really put anything there, like a number:

<!-- index.php -->
<!-- ... -->

<?php
    $pet1 = 'Chew Barka';
    $pet2 = 'Spark Pug';
    $pet3 = 'Pico de Gato';

    $pets = array($pet1, $pet2, $pet3, 14);
?>

It’s not a particularly exciting pet name, but when we refresh, we see “14” in our pet list.

An array is just a container that can hold anything. Each item in the array is given a unique key or index, which we can use to reference that item later if we need to. Heck, we can even put another array inside our array. We’ll try that craziness next!

Arrays have a lot more power, alternate syntaxes and a load of functions that can operate on them. But right now, let’s practice with the activities!