PHP is a powerful server-side scripting language offering a wide range of functions to facilitate various tasks. Functions in PHP are blocks of code that execute only when called. They can accept data, parameters as input, process it, and return an output using 'return' or simply execute code within the function without returning a value. Such functions are called void functions. If you use a function that PHP has already written for you, such as 'is_numeric' and many others, these are called built-in functions. If a function is located within a class, it is called a method. Regardless of whether you are working with built-in functions, writing your own, or using advanced concepts like closures, understanding functions is crucial for efficient PHP programming. Functions in PHP are a powerful tool that enables modularity, code reuse, and flexibility. You should use them whenever it makes sense in your code, while also professionally creating your own.
Many years ago, if you asked us how many types of functions there are, we would have thought about the basic division and answered four:
a function that takes no parameters and returns a value
a function that takes parameters and does not return a value
a function that takes no parameters but returns a value
a function that takes no parameters and do not return a value
Today, PHP has proven us wrong. There are many more types of functions in the PHP programming language, and today we will list the top 8 that you will often use in your projects.
To make things much clearer for you regarding the numerous functions in PHP, let's dive straight into the practical part when it comes to functions. This is the easiest way to go through and explain even 8 types of functions in the PHP programming language. Unlike previous lessons in this PHP tutorial, today we'll expand our PHP coding by using a CSS file in addition to Bootstrap. You might wonder why use CSS when you're using Bootstrap. The reason is simple. There are things in HTML and PHP coding that you can't always style using Bootstrap alone. So, for larger projects, you'll often find that CSS styling is used in addition to Bootstrap. Nowadays, there are systems that don't allow the use of Bootstrap for security reasons, they only use CSS, while we've never seen a project that prohibited the use of CSS. That's why you should always learn and know how to use HTML and CSS together with PHP. Our HTML & CSS tutorial will make it easier for you to learn or simply refresh your memory, click here.
Then we'll learn how to pass data from one PHP page with
an HTML form to another PHP page for further processing. Also, since there are
multiple functions, we'll place them in a separate PHP file and teach you how
to connect PHP files, so that you have the impression that separate functions
in another PHP file are available as if they were in the same one. This PHP
lesson might sound a bit complicated, but let us reassure you by coding
everything together, writing simple code that you can definitely use in your
projects.
Choose the Right Function for the Job: 8 Function Types for Better Code
