Functions are reusable pieces of code, often called Blocks, that as the name suggests, act as building blocks to piece together a program.
Each language has its own keyword for defining a function block.
fun keyword in Kotlin denotes a function, or method to wrap a reusable code block.
fun prepends the name of a function as illustrated below.
The structure of a Kotlin function
The function can take any number of parameters, and a return type.
A Kotlin function without a return value
If the function does not return a value, you can explicitly set its return type to