Everything you need to know about PHP for beginners.

I began programming with BBC BASIC in 1981 at the start of the computer revolution. I used my knowledge to improve the many different businesses I started. It came in very handy. Along the way I learnt and programmed in machine code, C++, and Java, but ultimately, I turned to PHP when I became more interested in apps, and in particular web applications. I hope the following helps others thinking about taking up this simple language.

But just before we dig into PHP, it’s important to know that learning PHP’s object oriented way of programming will get you further if you’re thinking of becoming a professional. And by far the best course I’ve found is from Gary Clarke, who lives and works in the UK. Use the coupon code QPCC2 to get a discount here.

Learn PHP with Quizzes and Tests: Answers Included

PHP is a popular programming language used for web development. It is known for its simplicity, flexibility, and ease of use. Learning PHP can be a valuable skill for anyone interested in building websites or web applications. Fortunately, there are numerous resources available online that offer PHP quizzes and tests with answers to help beginners learn the language.

Online PHP quizzes and tests with answers are a great way to test your knowledge and reinforce what you have learned. These resources are available for free and can be accessed from anywhere with an internet connection. They cover a wide range of topics related to PHP, including syntax, variables, data types, functions, and more. Whether you are a complete beginner or an experienced programmer, these quizzes and tests can help you improve your skills and become a better PHP developer.

In 2023, there are many options available for learning PHP online. These resources include interactive tutorials, video courses, online forums, and more. However, quizzes and tests with answers are particularly useful because they provide immediate feedback and help learners identify areas where they need to improve. By taking advantage of these resources, anyone can learn PHP and start building their own websites and web applications.

What is PHP?

Definition

PHP is an open-source server-side scripting language used for web development. It is a powerful tool that allows developers to create dynamic and interactive web pages. PHP code is executed on the server, and the resulting HTML is sent to the client’s web browser. PHP can be embedded in HTML code, and it can also interact with databases, making it an excellent choice for building web applications.

History

PHP was created in 1994 by Rasmus Lerdorf, a Danish-Canadian programmer. Originally, it was a set of Common Gateway Interface (CGI) scripts designed to help Lerdorf keep track of visitors to his personal website. He called it “Personal Home Page Tools” or “PHP Tools” for short. Over time, Lerdorf added more features and functionality, and in 1995, he released PHP version 2.0 as an open-source project.

In the years that followed, PHP grew in popularity, and a community of developers emerged to contribute to its development. In 1998, two developers, Andi Gutmans and Zeev Suraski, rewrote the PHP engine, creating the Zend Engine, which is still used in PHP today. The release of PHP 3.0 in 1998 marked the beginning of PHP’s widespread adoption, and by the early 2000s, it had become one of the most popular web development languages.

Today, PHP continues to evolve, with regular updates and new features being added to the language. It remains a popular choice for web developers, particularly for building dynamic web applications.

Quizzes and Tests

To test your knowledge of PHP, there are various quizzes and tests available online. Some of these include:

  • W3Schools PHP Quiz: This quiz contains 25 questions and covers a range of topics related to PHP. It is a great way to test your knowledge and identify areas where you may need to improve.
  • W3Docs PHP Basic Quiz: This quiz is designed for beginners and covers the basics of PHP. It contains 20 questions and is a good starting point for anyone new to the language.
  • ProProfs PHP Quizzes: ProProfs offers a range of PHP quizzes, including basic and advanced quizzes, as well as quizzes on specific topics like PHP arrays and PHP functions.

All of these quizzes provide answers and explanations, so you can learn from your mistakes and improve your understanding of PHP.

Basic Concepts in PHP

PHP is a server-side scripting language that is used to create dynamic web pages. It is one of the most popular programming languages and is widely used by developers all over the world. In this section, we will discuss some of the basic concepts of PHP.

Variables

Variables are used to store data in PHP. In PHP, variables are declared using the $ symbol followed by the variable name. Variables in PHP are case-sensitive. Here is an example:

$name = "John";
$age = 25;

Functions

Functions are blocks of code that can be reused throughout your PHP code. Functions can take arguments and can return a value. Here is an example of a function that takes two arguments and returns their sum:

function add($num1, $num2) {
    $sum = $num1 + $num2;
    return $sum;
}

Arrays

Arrays are used to store multiple values in a single variable. In PHP, arrays can be indexed or associative. Here is an example of an indexed array:

$cars = array("Volvo", "BMW", "Toyota");

And here is an example of an associative array:

$person = array("name" => "John", "age" => 25);

Operators

Operators are used to perform operations on variables and values. PHP supports a wide range of operators, including arithmetic, assignment, comparison, and logical operators. Here is an example of an arithmetic operator:

$x = 10;
$y = 20;
$sum = $x + $y;

Control Structures

Control structures are used to control the flow of execution in a PHP script. PHP supports a variety of control structures, including if/else statements, loops, and switch statements. Here is an example of an if/else statement:

if ($age < 18) {
    echo "You are not old enough to vote.";
} else {
    echo "You are old enough to vote.";
}

In conclusion, PHP is a powerful programming language that is widely used in web development. Understanding the basic concepts of PHP, including variables, functions, arrays, operators, and control structures, is essential for any PHP developer.

PHP Data Types

In PHP, variables can store different types of data, including strings, numbers, booleans, null, arrays, objects, and resources. Understanding the different data types is essential for writing effective PHP code.

Strings

A string is a sequence of characters enclosed in quotes. PHP supports single quotes (”) and double quotes (“”) for defining strings. Single quotes are faster and can only display literal strings. Double quotes can display variables and special characters.

Numbers

PHP supports several types of numbers, including integers, floats, and doubles. Integers are whole numbers, while floats and doubles are decimal numbers. PHP automatically converts numbers between these types as needed.

Booleans

A boolean is a data type that can have one of two values: true or false. Booleans are often used in conditional statements to control program flow.

Null

Null is a special data type that represents the absence of a value. A variable with a null value has not been assigned a value or has been explicitly set to null.

Overall, understanding PHP data types is crucial for writing effective PHP code. By using the correct data type for each variable, developers can ensure that their code is efficient and easy to maintain.

PHP OOP

PHP OOP stands for Object-Oriented Programming in PHP. It is a programming paradigm that allows developers to create reusable and modular code. PHP OOP is based on the concepts of classes and objects, inheritance, and encapsulation.

Classes

A class is a blueprint for creating objects. It defines the properties and methods that an object of that class will have. In PHP, a class is defined using the class keyword. Here is an example of a simple class:

class Person {
    public $name;
    public $age;
    
    public function sayHello() {
        echo "Hello, my name is {$this->name} and I am {$this->age} years old.";
    }
}

Objects

An object is an instance of a class. It has its own set of properties and methods, which are defined by the class. In PHP, you can create an object using the new keyword. Here is an example of creating an object of the Person class:

$person = new Person();
$person->name = "John";
$person->age = 30;
$person->sayHello(); // Output: Hello, my name is John and I am 30 years old.

Inheritance

Inheritance is a mechanism that allows a class to inherit properties and methods from another class. The class that inherits from another class is called the child class, and the class that is inherited from is called the parent class. In PHP, you can define a child class using the extends keyword. Here is an example of a child class that inherits from the Person class:

class Student extends Person {
    public $studentId;
    
    public function __construct($name, $age, $studentId) {
        $this->name = $name;
        $this->age = $age;
        $this->studentId = $studentId;
    }
    
    public function sayHello() {
        echo "Hello, my name is {$this->name}, I am {$this->age} years old, and my student ID is {$this->studentId}.";
    }
}

In this example, the Student class inherits the name and age properties, as well as the sayHello() method, from the Person class. It also has its own studentId property and a modified sayHello() method.

Conclusion

PHP OOP is a powerful programming paradigm that allows developers to write modular and reusable code. Classes and objects are the building blocks of PHP OOP, and inheritance allows developers to create child classes that inherit properties and methods from parent classes.

Working with Databases in PHP

PHP is one of the most popular programming languages for building dynamic web applications that interact with databases. Interacting with databases is one of the most crucial tasks in a web application. In this section, we will explore how to work with databases in PHP.

Connecting to a Database

Before you can interact with a database in PHP, you need to establish a connection to the database server. PHP provides several extensions to connect to different types of databases, such as MySQL, PostgreSQL, Oracle, MongoDB, and Sybase. Here is an example of connecting to a MySQL database using the mysqli extension:

$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database_name";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);

// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

Querying a Database

Once you have established a connection to the database, you can query the database to retrieve data. The most common way to query a database in PHP is by using the SQL language. Here is an example of querying a MySQL database using the mysqli extension:

$sql = "SELECT * FROM users";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // output data of each row
    while($row = $result->fetch_assoc()) {
        echo "id: " . $row["id"]. " - Name: " . $row["name"]. "<br>";
    }
} else {
    echo "0 results";
}

Inserting Data

You can also insert data into a database using PHP. Here is an example of inserting data into a MySQL database using the mysqli extension:

$sql = "INSERT INTO users (name, email, password) VALUES ('John Doe', 'john@example.com', 'password')";
if ($conn->query($sql) === TRUE) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

Updating Data

You can update existing data in a database using PHP. Here is an example of updating data in a MySQL database using the mysqli extension:

$sql = "UPDATE users SET name='Jane Doe' WHERE id=1";

if ($conn->query($sql) === TRUE) {
    echo "Record updated successfully";
} else {
    echo "Error updating record: " . $conn->error;
}

Deleting Data

You can also delete data from a database using PHP. Here is an example of deleting data from a MySQL database using the mysqli extension:

$sql = "DELETE FROM users WHERE id=1";

if ($conn->query($sql) === TRUE) {
    echo "Record deleted successfully";
} else {
    echo "Error deleting record: " . $conn->error;
}

In conclusion, working with databases in PHP is a crucial task for building dynamic web applications. By using the appropriate SQL queries, you can easily interact with databases and perform various operations such as inserting, updating, and deleting data.

PHP and HTML

PHP is a server-side scripting language that can be used to create dynamic web pages. HTML, on the other hand, is a markup language used to create static web pages. PHP can be used to generate HTML code dynamically, making it possible to create web pages that can change based on user input or other factors.

Echoing HTML

One of the most common uses of PHP with HTML is to echo HTML code. This is done using the echo statement in PHP. The echo statement can be used to output any valid HTML code, including tags, attributes, and content.

For example, the following PHP code will output a simple HTML page:

<?php
echo "<html>";
echo "<head><title>My Page</title></head>";
echo "<body><h1>Welcome!</h1></body>";
echo "</html>";
?>

This code will generate a basic HTML page with a title of “My Page” and a heading that says “Welcome!”.

Forms

HTML forms are a common way to collect user input on a website. PHP can be used to process the data submitted through a form and generate a response based on that data.

To create an HTML form, you can use the form tag in HTML. You can then use various input types, such as text, checkbox, and radio, to collect data from the user.

Once the user submits the form, the data is sent to the server using either the GET or POST method. PHP can then be used to process the data and generate a response.

For example, the following PHP code will process a simple form that collects the user’s name and age:

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  $name = $_POST["name"];
  $age = $_POST["age"];
  echo "Hello, $name! You are $age years old.";
}
?>

<form method="post">
  <label for="name">Name:</label>
  <input type="text" id="name" name="name"><br>

  <label for="age">Age:</label>
  <input type="text" id="age" name="age"><br>

  <input type="submit" value="Submit">
</form>

This code will generate a form with two input fields, one for the user’s name and one for their age. When the user submits the form, the PHP code will process the data and output a message that includes the user’s name and age.

In conclusion, PHP and HTML are two essential technologies for web development. By combining them, developers can create dynamic web pages that can respond to user input and other factors. With the help of quizzes and tests, developers can improve their PHP skills and create more efficient and effective web applications.

PHP Configuration and Services

PHP Configuration and Services are an essential part of PHP programming. In this section, we will discuss the various aspects of PHP Configuration and Services.

PHP Configuration

PHP Configuration refers to the settings and options that are available in PHP. These settings can be changed to suit the needs of the developer. The PHP Configuration can be accessed using the phpinfo() function. This function displays all the information about PHP Configuration.

The PHP Configuration is divided into several categories, including General, PHP Core, Apache, and Modules. Each category contains several settings that can be changed. Some of the important settings in PHP Configuration include memory_limit, post_max_size, upload_max_filesize, and display_errors.

PHP Services

PHP Services refer to the various services that are available in PHP. These services can be used to perform various tasks in PHP programming. Some of the important PHP Services include MySQL, SQLite, and PostgreSQL.

MySQL is a popular PHP Service that is used to manage databases. SQLite is a lightweight PHP Service that is used to store data in a file-based database. PostgreSQL is a powerful PHP Service that is used for enterprise-level applications.

In addition to these services, PHP also provides support for other services such as LDAP, FTP, and IMAP. These services can be used to perform tasks such as authentication, file transfer, and email handling.

Overall, PHP Configuration and Services are an essential part of PHP programming. By understanding the various aspects of PHP Configuration and Services, developers can create powerful and efficient PHP applications.

PHP Quizzes and Tests

PHP Quiz Overview

PHP quizzes are a great way to test your knowledge of PHP programming language. These quizzes are designed to help you assess your understanding of the basics of PHP, including variables, data types, loops, functions, and more. PHP quizzes are usually multiple-choice and have a set number of questions with a time limit.

One of the most popular PHP quizzes is offered by W3Schools. This quiz contains 25 questions and has no time limit. You will receive one point for each correct answer, and your total score will be displayed at the end of the quiz. Another popular PHP quiz is offered by W3Docs, which contains 20 questions with no time limit. You will receive 5% for each correct answer, and you will receive a certificate of achievement upon passing the quiz.

PHP Quiz Questions and Answers

PHP quiz questions cover a wide range of topics related to PHP programming language. Some of the most common topics include variables, data types, loops, functions, arrays, and strings. Multiple-choice questions are the most common type of question in PHP quizzes. These questions usually have four options, and you must select the correct answer.

Here are some sample PHP quiz questions:

  1. What is the correct way to declare a variable in PHP?
    1. $x = 1;
    2. var $x = 1;
    3. declare $x = 1;
    4. none of the above
  2. What is the output of the following code? $x = 10; while($x > 0) { echo $x; $x–; }
    1. 12345678910
    2. 10987654321
    3. 9876543210
    4. 123456789

Answers:

  1. $x = 1;
  2. 10987654321

PHP Test Overview

PHP tests are similar to quizzes, but they usually have a set number of questions, a time limit, and a grading system. PHP tests are designed to test your understanding of PHP programming language in greater depth than quizzes. PHP tests are often used by employers to assess the knowledge and skills of job candidates.

PHP Test Questions and Answers

PHP test questions cover a wide range of topics related to PHP programming language. Some of the most common topics include variables, data types, loops, functions, arrays, strings, and object-oriented programming. Multiple-choice questions are the most common type of question in PHP tests. These questions usually have four options, and you must select the correct answer.

Here are some sample PHP test questions:

  1. What is the difference between single quotes and double quotes in PHP?
    1. Double quotes can be used to enclose variables, while single quotes cannot.
    2. Single quotes can be used to enclose variables, while double quotes cannot.
    3. Single quotes and double quotes are interchangeable.
    4. None of the above.
  2. What is the output of the following code? $x = 5; $y = 3; echo $x % $y;
    1. 1
    2. 2
    3. 0
    4. 3

Answers:

  1. Double quotes can be used to enclose variables, while single quotes cannot.
  2. 2

Overall, PHP quizzes and tests are a great way to assess your knowledge of PHP programming language and improve your skills. By taking these quizzes and tests, you can identify your strengths and weaknesses and focus on areas that need improvement.

Conclusion

Learning PHP is a great way to dive into web development and create dynamic websites. With the basics covered, beginners can start building their skills and taking on more complex projects.

Online resources, such as quizzes and exercises, can be a valuable tool in learning PHP and testing one’s knowledge. The quizzes and tests with answers can help learners identify areas where they need to improve and reinforce their understanding of the language.

By practicing and applying PHP concepts, beginners can become proficient in the language and develop the skills needed to create robust web applications. With its versatility and popularity, PHP is a valuable skill to have in the tech industry.

Overall, learning PHP takes time and effort, but with the right resources and dedication, anyone can become proficient in the language. By taking advantage of online resources, such as quizzes and exercises, beginners can gain the knowledge and skills needed to succeed in web development.

About the author 

Quentin Pain

Quentin Pain started his first business, a courier company aged 23. He sold it 4 years later and used the profits to start a recording studio. A couple of albums later, he started two software companies, the last one being Accountz, which he grew from zero to 36,000 customers and retired from in January 2013. He is a director of ProofMEDIA, a specialist digital consulting business. He's also a published author (including a Dummies title), and has won many awards including the IAB Small Business Mentor of the Year. Copywriting is his speciality and he runs 3 groups on Facebook under the Science of Copywriting brand, which combined has well over 180,000 members. Quentin is also Founder of the International Copywriters Association and former SEO Lead for Circle Health Group, the UK's largest private hospital group.