PHP Snippets: Variables

This post is part of the PHP Snippets series where I will be covering the basics of developing in PHP.

Variables are used to store data that can be referenced and used throughout your code. In PHP, a variable is declared using a dollar sign ($) followed by the variable name:

$fruit = 'apples';
$count = 5;

Variable names in PHP are case-sensitive, must start with a letter or underscore, and can contain letters, numbers, and underscores. By convention, variable names are written in camelCase or with underscores to separate words:

$fruitName = 'apples';
$fruit_count = 5;

PHP is a loosely typed language, which means you do not need to declare the type of a variable before assigning a value to it. PHP will automatically determine the type based on the value assigned:

$fruit = 'apples';    // string
$count = 5;           // integer
$price = 1.99;        // float
$inStock = true;      // boolean

Variables can be reassigned at any point, and their type can change when a new value is assigned:

$value = 10;
$value = 'ten';

You can check the current value of a variable at any time using echo or, for debugging purposes, var_dump() which also outputs the type:

$count = 5;
var_dump($count);