Learn PHP basics with hands-on practice in hello world in PHP, variables in PHP, functions in PHP, arrays in PHP, PHP inheritance, PHP exceptions, and more.

This interactive course introduces you to the fundamentals of PHP programming, one of the most widely used languages in web development. Starting with a simple hello world in PHP, you’ll explore the basics, including PHP output, variables in PHP, and PHP data types. You’ll also learn about PHP constants, arithmetic operators, comparison operators, logical operators, and assignment operators.

The course progresses into conditional statements in PHP, PHP switch, and various loops such as PHP for loop, PHP while loop, and more. You will then dive deeper into functions in PHP, understand PHP variable scope, and learn PHP pass by reference or value. Additionally, you’ll gain a working knowledge of strings in PHP, PHP string operations, and handling arrays in PHP, including PHP multidimensional arrays.

In the advanced sections, you’ll explore classes in PHP, inheritance, constructors, and destructors, handling PHP exceptions with PHP throw and catch exceptions.

Learn PHP

# What is Pass by Reference?

When passing *arguments* by **pass by reference**, the *original* value is passed. Therefore, the *original* value gets altered. In **pass by reference**, we actually pass the value using *ampersand* sign `&`. The additional `&` is very important: it tells the *compiler* that the data is a *reference* to the *value* rather than simply the value itself.

# Example: Swap Numbers
Now let's redefine the `interchange` *function* from the example in the [previous](https://www.educative.io/courses/learn-php/pass-by-value) lesson. 

This lesson introduces the ways by which we pass values to a function by reference.


PHP Basics

PHP Variables

PHP Operators

PHP Conditional Statements

PHP Loops

PHP Functions

PHP Strings

PHP Arrays

PHP Assessment 1

PHP Classes

Exception Handling in PHP

PHP Assessment 2

Pass by Reference

What is Pass by Reference? #