The "Math" Object Type - The Math Container

JavaScript Tutorials - Herong's Tutorial Examples

∟The "Math" Object Type - The Math Container

This section provides a quick description and a tutorial example script on the 'Math' built-in object type. There is only one default 'Math' object called 'Math' that holds all math properties and functions.

The "Math" object type is a special built-in object type, that is used by the host environment to create a single "Math" object as a container for many mathematics related properties and functions. It has the following main features:

There is no way you can create your own "Math" objects, because the "Math()" constructor is not accessible.
The host environment creates the default "Math" object.
The default "Math" object has several value properties: E, LN10, LN2, PI, SQRT2, etc.
The default "Math" object has many function properties (methods): abs(), floor(), ceil(), round(), sin(), cos(), random(), etc.

Here is a tutorial example script showing some of those features:

// Math_Object_Type.js
// Copyright (c) 2013 HerongYang.com. All Rights Reserved.

   // Creating your own "Math" objects is not allowed
   // var myObject = new Math();

   // Checking this object
   println("\nAbout this \"Math\":");
   println("   Type = "+(typeof Math));
   println("   Instance Of Object: "+(Math instanceof Object));
   println("   Instance Of Function: "+(Math instanceof Function));
   println("   Instance Of Math: "+(Math instanceof Math));
   println("   toString(): "+Math.toString());

   println("\n\"Math\" value properties:");
      println("   Math.E = "+Math.E);
      println("   Math.PI = "+Math.PI);
      println("   Math.SQRT2 = "+Math.SQRT2);

   println("\nCalling \"Math\" function properties - methods:");
      println("   Math.sqrt(2) = "+Math.sqrt(2));
      println("   Math.sin(Math.PI) = "+Math.sin(Math.PI));
      println("   Math.abs(-17.78) = "+Math.abs(-17.78));
      println("   Math.ceil(-17.78) = "+Math.ceil(-17.78));
      println("   Math.floor(-17.78) = "+Math.floor(-17.78));
      println("   Math.round(-17.78) = "+Math.round(-17.78));
      println("   Math.random() = "+Math.random());

If you run this script with "jrunscript", you will get:

About this "Math":
   Type = object
   Instance Of Object: true
   Instance Of Function: false
   Instance Of Math: false
   toString(): [object Math]

"Math" value properties:
   Math.E = 2.718281828459045
   Math.PI = 3.141592653589793
   Math.SQRT2 = 1.4142135623730951

Calling "Math" function properties - methods:
   Math.sqrt(2) = 1.4142135623730951
   Math.sin(Math.PI) = 1.2246467991473532e-16
   Math.abs(-17.78) = 17.78
   Math.ceil(-17.78) = -17
   Math.floor(-17.78) = -18
   Math.round(-17.78) = -18
   Math.random() = 0.4715524330340368