How do variables work in PHP?

Variables are assigned in a typical manner. Normal variables are preceded with a $ and assigned to with =. Any variable can be used in an array by including a key in square brackets after the variable.

For a regular array, a number is used as the key.
For an associative array, a quotes enclosed string (or another variable) is used.
The function ‘array’ can also be used to create arrays of either type.

The code below illustrates these features (lines beginning with “//” are comments):


// Normal variable assignment
$person = "Bob";// Assigning to a regular array
$fruit[0] = "apple";
$fruit[1] = "grape";
$fruit[2] = "orange";// Assigning to an associative array
$mother['kitten'] = "cat";
$mother['puppy'] = "dog";

// Using the array function for a regular array
$fruit = array('apple','grape','orange');

// Using the array function for an associative array
$mother = array('kitten' => 'cat', 'puppy' => 'dog');

// The following line prints "Bob's cat ate an orange."
echo "$person's $mother['kitten'] ate an $fruit[2].";
?>

One of the most powerful features of PHP is its easy access to requested variables. For instance, consider the following short form:


<form action="form_handler.php?posted=true" method="post">
<input name="formvar">
<input value="Submit Query" type="submit">
</form>

On submitting the form, the value of the variable “formvar” will be available to the form_handler.php script simply as


$_POST['formvar']

and the variable posted simply


$_GET['posted'].

This is true for all POST and GET form calls.

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