A function literal

One of the most important concepts in JavaScript is that the functions are the primary unit of execution. Functions are the pieces where you will wrap all your code, hence they will give your programs a structure.

JavaScript functions are declared using a function literal.

Function literals are composed of the following four parts:

• The function keyword.

• An optional name that, if specified, must be a valid JavaScript identifier.

• A list of parameter names enclosed in parentheses. If there are no parameters to the function, you need to provide empty parentheses.

• The body of the function as a series of JavaScript statements enclosed in braces.

A function declaration

The following is a very trivial example to demonstrate all the components of a function declaration:

function add(a,b){
  return a+b;
}
c = add(1,2);
console.log(c);  //prints 3

The declaration begins with a function keyword followed by the function name. The function name is optional. If a function is not given a name,...