break ends execution of the current for, foreach, while, do-while or switch structure.
The case statement represents one option in a switch instruction.
Basic class definitions begin with the keyword class, followed by a class name, followed by a pair of curly braces which enclose the definitions of the properties and methods belonging to the class.
A constant is an identifier (name) for a simple value.
continue is used within looping structures to skip the rest of the current loop iteration and continue execution at the condition evaluation and then the beginning of the next iteration.
The default statement represents a catch-all case in a switch instruction.
Object interface allow you to create code which specifies which methods a class must implement, without having to define how these methods are handled.
The switch statement is similar to a series of IF statements on the same expression. In many occasions, you may want to compare the same variable (or expression) with many different values, and execute a different piece of code depending on which value it equals to. This is exactly what the switch statement is for.
Traits are a mechanism for code reuse in single inheritance languages such as PHP.