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.
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.
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 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.
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.
Introduction to PHP
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.