In PHP there are two ways you can pass arguments to a function: by value and by reference. It turns out that creating the facade object has only a negligible impact on performance. So what does the syntax for defining a function look like? To declare a type for the function return, add a colon ( In PHP, we can define Conditional function, Function within Function and Recursive function also. All Rights Reserved. A function is a block of statements that can be used repeatedly in a program. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. It's logical (and perfectly legal in PHP) to define B inside of A's definition, like so: