Functions

What is a function?

  • A function is a subprogram designed to perform a particular task.
  • Functions are executed when they are called. This is known as invoking a function.
  • Values can be passed into functions and used within the function. This is done through arguments that the function may accept
  • Functions can return a value. In JavaScript, if no return value is specified, the function will return undefined.
  • Javascript contains some built-in functions, external libraries like p5 expand the set of these functions.

Defining a Function

To define a function the basic syntactical structure is used,

function name(parameters) {
    // code in the function
}

Calling a Function

Calling/Invoking a function asking it to run at the point at which you have called it. Think of it like excecuting a keyboard shortcut, the function to make a new window is defined, and when the computer gets ‘ctrl+N’ it calls (runs) the new window function.

Syntax,

functionName(arguments);

If your function was defined without parameters,

functionName();