2025 PHP for Beginners: every line used is fully explained

We follow the coding tradition and start with Hello, World!

The 'Hello, World!' script is a common starting point for most coding courses and we follow this traditional starting point in PHP for Beginners.

The actual PHP code is straightforward but we learn the basics of the code structure that can help with more advanced coding examples.

I think there is always something special about writing your first lines of code. I know when I do this in a normal classroom with students there is always a 'wow' moment as they actually create something for the first time and see the output of their coding 'skills'.

Enjoy this simple lesson and remember that it will not be long before you are writing much more complex PHP code.

Learn how to start a PHP code block and how to avoid and handle some basic common errors.

• closing php tags and when and why we can omit them
• missing semi-colons

The fundamentals of any good piece of PHP code starts with an understanding of the basics. In this lesson we will look at how we start a PHP code block by opening a PHP tag and when it is OK to omit the closing PHP tag. You would be amazed at how many coders are caught out by this very simple error.

Most of the errors beginner PHP coders encounter come from missing semi-colons on the end of each line. Those of you who come from a language where line terminators are not required will need to ensure that you finish each line with a semi-colon. 

The error messages you receive in your browser are a great way to help you identify where your error is and to quickly fix it.

The only way to get better at PHP coding is to keep practising the basics and to form good habits.

Enjoy the lesson.

Learn how to name a variable correctly in PHP.

• What are PHP variables

• How do you name a variable in PHP

This lesson covers another fundamental step on your progress towards learning how to code in PHP.

One of the things you will need to do within most of your code blocks is to create and use variables.

In this lesson we look at what is a valid PHP variable and what is not a valid PHP variable.

All variables start with a dollar symbol $ and then either a letter or underscore and can then include any alphanumeric character or underscore. Variables in PHP can not start with a number.

E.g. $name, $_myVariable

There are many coders out there who have their own methods and naming conventions for variables. That is fine if they are not sharing code and only use their code for their own use or within a limited team.

I would urge you to use variable names that make sense and to always comment your code with explanations if you are going to be working on external projects.

Start with good habits from day one and you will find your coding journey so much easier.

Please read the attached document for further information about variables.

Enjoy the lesson!

You will learn how to assign values to variables in PHP

I think it is fair to say that most PHP code written will include the use of variables somewhere. 

Think of a variable as a box in which we can store a piece of information. We can then move that information around and pull it out of the box at any time and use it.

REMEMBER from the previous lessons that:

• A PHP variable always starts with a $ sign and then a letter or underscore character. 
• We can not start a variable name with a number!
• A variable name can contain A - z, 0 - 9, _

It is a good idea to learn the different variable types such as integer, string, decimal, date etc.

We will briefly look at the PHP online resource manual and see what data types are available for us to use.

Get into good habits early and comment your code!

I show you how to add comments to your PHP code and how to comment out sections of code.

It is always a good idea to comment your code, especially if you have a longer project.  When you come back to your code after several weeks, months, or even years, it makes it much easier to remember what you did and what variables actually mean.

In this lesson we learn how to use PHP echo and print functions to view code output.

There does not seem much point in learning to code if no-one is going to see any of your output. So, in this lesson, we look at the difference between echo and print.

There are arguments that echo is faster than print and vice-versa. There are also some other subtle differences in terms of output of singular versus multiple arguments. However, we will not worry about speed differences between the two. The differences are so imperceptible that is really is not worth worrying about!

I rarely use print myself and rarely come across it when coding. 

Enjoy the lesson!

In this lesson you will learn how to use concatenation.

You will learn how to use the addition + operator in PHP.

We will also look at shortcut methods for adding numbers.

We now delve into performing calculations with PHP and start with very simple addition and subtraction operators. Hopefully you do not have a fear of math! However, everything is kept quite simple at these early stages of learning to code in PHP.

We will use our understanding of variables and how to assign values. We will then see how we can add and subtract variable values in PHP.

The process is relatively straightforward and if you recall your algebra class from school then you will see the similarities.

Remember that all code from the lesson can be downloaded from the resources section (see the top left of the browser window for the resources link).

In the next lesson we will be looking at multiplication and division using PHP. You may wish to think about how those operations are performed in PHP prior to watching the next lesson after this. See if you can figure it out.

Enjoy the lesson and, as my old math teacher would write on the top of his worksheets, "no calculators allowed".

You will learn how to multiply and divide numbers in PHP.

The multiplication symbol in PHP code is the asterisk *.

The division symbol in PHP code is the forward slash /.

You will learn how to use the PHP modulus operator.

This can be a very powerful PHP operator to use. 

It is used to find what the remainder is when one number is divided by another number.

E.g. If we take the number 20 and divide it by 3 then there will be a remainder of 2.

The actual PHP operator for modulus is the percentage symbol %.

You will learn how to raise a number to a given power

In this challenge you will create a basic calculator

Solution for the back to school challenge

Downloadable file containing the code for the back to school challenge

In this lesson you will learn more concatenation strategies.

Another challenge.

The solution to the What's In a Name challenge

The full code of the solution to the WHAT'S IN A NAME challenge

Logical and comparison operators

You will learn how to use the IF statement

You will learn how to use the IF ELSE statement. This lesson builds upon the previous lesson and provides you with more examples.

You will learn how to use the ELSEIF statement

More logical and comparison operators

In this lecture you will learn how to increase and decrease a variable value

In this PHP for Beginners lesson you will learn how to use a FOR loop.

Loops are very important and extremely useful when cycling through variable values, particularly when it comes to using database records (although we don't cover that in this course).

There are different methods we can employ to loop through values and the FOR loop in PHP is just one such way.

You will learn how to use a WHILE loop

The Multiples challenge

Time for another challenge. In this task you have to create a loop which will create a 6 times table

Video solution for the multiplication tables task

Code for the multiplication tables task

The Fizz Buzz Challenge

In this challenge you need to replicate the game of FIZZ BUZZ.

This is known as a common interview question for coders and one which I use a lot in the classroom.

The challenger makes you think about the logical order of test conditions.

Video solution for the Fizz Buzz challenge

Code for the fizz buzz challenge

You will learn how to use the PHP reference manual

You will learn how to generate a random number in PHP

This challenge will test your understanding of simple functions and conditional statements.

Challenge - Odds and Evens

Challenge Solution: Odds and Evens

Full code to the Odds and Evens challenge

In this task you need to calculate the area of a circle using the PI() function and then the ROUND() function to round your answer.

Challenge: Who ate all the pi?

Video solution to the WHO ATE ALL THE PI task

Downloadable code for the WHO ATE ALL THE PI task

How to use the date() function in PHP

In this task you will have to format various dates by using the DATE() function

Challenge: Carpe Diem

Video solution to the CARPE DIEM task

Downloadable code for the CARPE DIEM task

We look a little bit more at some of the available date functions before taking on the next challenge.

This tasks involves counting the number of days until Christmas.

Challenge: Santa Claus is Coming to Town

Video solution to the SANTA CLAUS IS COMING TO TOWN challenge

Downloadable code to the SANTA CLAUS IS COMING TO TOWN challenge.

You will learn how to create a basic HTML page structure including:

• doctype
• tag use
  • opening and closing tags
• head section and title
• body section

You will learn the structure of a basic form and create one from scratch. No styling will be applied. We will just focus on the form structure.

You will learn how to send your form data to a PHP processing script. You will then learn how to check that data has been sent and how to assign it to variables.

This task involves creating a user input form and taking the temperature input and converting it from degrees C to degrees F

Challenge: Temperature Conversion

Video solution to the temperature conversion task

Downloadable file containing the code to the temperature conversion task

You will learn how to use strlen() in order to find the length of a string.

NOTE: If you are using a different character set then you may find that the result for strlen is not what you expected.  strlen works for a standard English alphabet.  If you have different characters e.g. ä

then you will need to use mb_strlen

In this task you will accept a user input and check the length of the string and then tell them how long the string is.

Video solution to the HOW LONG IS A PIECE OF STRING challenge

Downloadable code for the HOW LONG IS A PIECE OF STRING challenge.

NOTE: If you are using a different character set then you may find that the result for strlen is not what you expected.  strlen works for a standard English alphabet.  If you have different characters e.g. ä

then you will need to use mb_strlen

In this lesson I show you how to count the number of words in a sentence.

NOTE: If you are using a different character set then you may find that the result for strlen is not what you expected.  strlen works for a standard English alphabet.  If you have different characters e.g. ä

then you will need to use mb_strlen

In this lesson I show you how to replace characters in a string. This function has many uses, one of which could be as a bad word filter.

In this lesson we look at the str_shuffle() function

Yesterday you received a strange message from HQ which simply said: str_rot13()

Today you received a long coded message:

Rafher gung lbh orpbzr snzvyvne jvgu cuc shapgvbaf nf gurl ner rkgerzryl hfrshy.

Your task is to decode the message and act on it.

Challenge: Mission Impossible

Solution to the MISSION IMPOSSIBLE challenge

<?php

//original messsage

$message = "Ensure that you become familiar with php functions as they are extremely useful.";

//coded message

$encoded = str_rot13($message);

echo $encoded;

echo "<br>";

//decoding the message

$return = str_rot13($encoded);

echo $return;

In this lesson we look at the difference between double and single quotes.

In this lesson we look at how we can escape strings. I show you the use of double and single quotes.

In this challenge you will escape strings in order to have valid output. Not as easy as it first sounds!

Challenge: The Great Escape

The video solution to THE GREAT ESCAPE challenge

Downloadable code for THE GREAT ESCAPE challenge

You will learn what an array is in PHP

You will learn how to output data from an array. This is extremely useful for when we start to connect with databases.

You will learn how to split an array at a given point and in a given length using array_slice()

In this task you will:

• create a user input form
• create a script to check if it is a valid ISBN number

Challenge: ISBN Checker

Video tutorial solution to the ISBN checker challenge

Downloadable file of the solution to the ISBN checked challenge

In this challenge you will use your knowledge of arrays and strings to filter out inappropriate words from user inputs

Challenge: Mind Your Language

Video solution for the MIND YOUR LANGUAGE challenge

In this lesson you will learn how to sort data in an array and then output the results.

I will show you the following functions:

• sort()
• rsort()

You will learn how to use the explode() and implode() functions on strings.

You will learn how to add items to an array using array_push() and array_unshift()

In this challenge you will take a list of 10 cities and place them into an array. You will then sort them alphabetically and output the result as an ordered list. For example, the output may look like this:

1. Amsterdam
2. Berlin
3. London
4. Paris
5. ...etc

Challenge: Around the World in 80 Days

Video solution for the AROUND THE WORLD IN 80 DAYS challenge.

Downloadable code for the AROUND THE WORLD IN 80 DAYS challenge

You will learn how to remove single elements from an array using array_pop() and array_shift()

In this lesson we learn how to use the array_slice() function to split an array.

In this task you will need to take a series of temperatures and place them into an array, then order them, then find the 5 hottest temperatures and output them.

Challenge: It's getting hot in here

Video solution for the IT'S GETTING HOT IN HERE challenge

Code for the challenge: It's getting hot in here

You will learn how to shuffle an array and select a random element from an array

In this task you will generate a random card from a pack of 52 playing cards. You will need to use the array_rand() function to return a random element from an array.

Challenge: Pick a card, any card

Video solution for the PICK A CARD, ANY CARD challenge

Downloadable code for the PICK A CARD, ANY CARD challenge

In this task you need to consider user inputs and how we can validate these. In this activity you will be validating a credit card number.

Although most online stores process payments via external payment processors, it is still a nice little activity to get you thinking about the logic behind the code...something that most beginners find quite challenging.

NOTE: you will need to spend some time thinking about the logic behind the code.

Challenge: Let's go shopping

Video solution to the LET'S GO SHOPPING CHALLENGE

NOTE: the logic within this solution does take some thought.  It is recommended that you plan your solution carefully and use pseudo-code.

Downloadable code for the LET'S GO SHOPPING challenge

You will learn how to understand associative arrays and how to structure them. We look at the terms KEY and VALUE.

You will learn how to output the associative array.

You will learn how to use a FOREACH loop to output the KEY VALUE pairs in an associative array.

In this task you will need to take an associative array and output the elements in order using asort() and ksort()

Challenge: Capital cities of the world

Video solution of the CAPITAL CITIES OF THE WORLD challenge

Code for the Capital Cities of the World challenge