PHP Arrays
There are two data structures that are very common and useful: lists and maps. A list is an ordered set of elements, whereas a map is a set of elements identified by keys. An array is a data structure that implements both, a list and a map.
PHP Strings
Strings are concatenations or series of characters that you cannot see at once when searching for something. Instead, you have to look one by one and keep track of what the content is. PHP has many predefined functions that help you in interacting with strings. Characters are letters, numbers, and punctuation. When a number is used as a character, it is just a stored character, the same as a letter. It can’t be used in arithmetic.
PHP Operators
Operators are elements that take some expressions, operands, and perform actions on them to get a result. An expression is almost anything that has a value. Variables, numbers, or text are examples of expressions. Operators expect expressions of a specific type, for example, arithmetic operators expect either integers or floats.
PHP Data Types
Values stored in a variable or in a constant are stored as a specific type of data. PHP provides eight data types.
PHP Constants
PHP constants are similar to variables. Constants are given a name, and a value is stored in them. However, they can’t be changed by the script. After you set the value for a constant, it stays the same. For example, if you used a constant for age and set it to 21, the value is always and forever 21.
PHP Variables
Variables are containers used to hold information. Variables keep a value for future reference. A variable has a name, and information is stored in the variable. For example, you might name a variable $age and store the number 12 in it. Information stored in a variable can be used later in the script. This value can change if you want it to; that is why they are called variables.
PHP Files
In order to write PHP code, you have to start the file with <?php. You can also finish the file or PHP code with ?>. You can mix PHP code with other content, like HTML, CSS, or JavaScript, in your PHP file as soon as you enclose the PHP bits with the <?php and ?> tags.
Introduction to PHP
PHP is a server-side language, which means it runs on the server before anything is sent to the user’s computer. This is in contrast to client-side languages, where the code is sent to the user’s computer to be processed locally with languages like JavaScript.
Autoloading Classes
In order to use a class, you need to include the file that defines it. Autoloading is a PHP feature that allows your program to search and load files automatically given some set of predefined rules. Each time you reference a class that PHP does not know about, it will ask the autoloader.
Article Structured Data
Proper structured data in your news, blog, and sports article page can enhance your appearance in Google Search results. Enhanced features include entry in a top stories carousel and rich result features such as headline text and larger-than-thumbnail images. Your content may also be automatically turned into an action on the Google Assistant.