Create class properties in previous versions of PHP

Instructor: [0:00] We now have a value passed to the constructor, but a var_dump really won't be doing anything for us. We need to assign this value to a variable.

[0:10] In classes, you do this with something called a class property. You can think of classes as representing a specific entity, and properties representing values related to that entity.

[0:22] Just like in this example, the author is the entity, and the author name would be a good property. We can also have other properties like gender, age, location, and so on.

[0:35] This lesson covers class properties in versions of PHP that came before PHP 8.

[0:43] I included it first though because it will help you understand how scope and properties work within classes, or if you needed to work with legacy code that was created in versions before PHP 8.

[0:56] You can create a class property by using a scope keyword right at the start of a class.

[1:02] We will get into scopes in a bit more detail later on. For now, let's just create a new property with the public scope. This is the default scope for functions and properties. Next comes the name of the property and this will be a variable name. Let's just name this $name.

[1:25] You can also define a data type for this class property, which would go in between the scope and the name of the property. This is a string, so we can cast this as the string data type. Next we will update our constructor to assign it to this property.

[1:43] Within our constructor, we will first use the $this keyword. The $this keyword references the class that you are currently within. This is the specific instance of this author class, which is actually the author variable. Next we will use a dash and greater than sign which is referred to as an arrow.

[2:08] Next comes the property name, which in this case is name. This is derived from the name of our property without the dollar sign. Finally, we can just set this value equal to our argument name, which is $name, which comes from our argument.

[2:28] You can define as many properties as you like here by duplicating out the lines and then changing the names and value types of each property. You can also pass in multiple arguments and assign them to those property names, if you wish, depending on your needs.