Functions in JavaScript

The illustration gives an overview of how the program flow would look for a function. Let’s list the properties of a function.

Function features

A function has the following properties:

• A list of arguments which can be anything and is optional. This is the input to the function.

• A program block is executed on the invocation of the function.

• An output that is returned after the function finishes executing using a return statement.

With these features in mind, let’s learn the corresponding JavaScript syntax.

Basic function syntax and semantic

We know a function can have an input, a program block where all the instructions that would be executed reside, and an output that is returned by the function. Below is an outline of a function in JavaScript.

Here, the function starts with a function token, then the name of the function. This is followed by arguments in parentheses, and concludes with a set of instructions encapsulated within the brackets including a return statement which uses the return token within the set of instructions. ...