Functions

Declarative vs. Dynamic Functions

In JavaScript, functions can be categorized into two main types:

• Declarative/Static Functions: These functions have a fixed structure and are not redefined during runtime.
• Dynamic/Anonymous Functions: These functions can be evaluated multiple times, and they can be anonymous or dynamically created.

Defining Functions

There are different ways to define functions in JavaScript:

• Using the Function Constructor:

  var variable = new Function("param1", "param2", ..., "paramn", "function body");

  Functions created with the Function Constructor are parsed every time they are evaluated.

• Using Function Literal:

  var func = (params) => {
      // statements;
  };

  This type of function, defined using a function literal, is parsed only once, making it a more efficient way of defining functions.

Function Literals

When a function is used within an expression in another statement, it is considered a function literal, regardless of the expression it is used in.

Function Properties

JavaScript functions have certain properties that can be accessed:

• functionName.length: This property returns the number of arguments expected by the function.