PHP Variable Variables (original) (raw)

Summary: in this tutorial, you’ll learn about PHP variable variables and how to apply them effectively.

Introduction to the PHP variable variables #

Typically, you have a variable with a predefined name. For example, the following defines a variable with the name $title that holds a string.

`<?php

$title = 'PHP variable variables';`Code language: PHP (php)

In PHP, the name of a variable can be derived from the value of another variable. For example:

`<?php

$my_var= 'title'; my_var = 'PHP variable variables';

echo $title;`Code language: PHP (php)

Try it

Output:

PHP variable variablesCode language: PHP (php)

How it works.

• First, define a variable $my_var that holds the string 'title'.
• Second, define a variable variable that holds the string 'PHP variable variables'. Note that we use double $ signs instead of one. By doing this, we technically create another variable with the name $title.
• Third, display the value of the $title variable.

Suppose that you have the following folder and files:

├── inc | └── home.php └── index.phpCode language: PHP (php)

In the index.php, you define the following view() function that loads the code from a file specified by the $file parameter:

`<?php

function view(string $file): void { require DIR . $file; }`Code language: PHP (php)

To pass the data to the script specified by the $file, you can add a second parameter to the view() function like this:

`<?php

function view(string file,arrayfile, array file,arraydata): void { require DIR . $file; }`Code language: PHP (php)

From the $file script, you can access the elements of the $data array.

The following example uses the view() function to load the code from the home.php script and pass an array of two elements to it:

`<?php

function view(string file,arrayfile, array file,arraydata): void { require DIR . '/' . $file; }

view( 'inc/home.php', [ 'title' => 'Home', 'heading' => 'Welcome to my homepage' ] );`Code language: PHP (php)

In the home.php, you can access the $data array like this:

`