prototype

Summary

Returns a reference to the prototype for a Boolean.

Syntax

boolean.prototype

Examples

Defines a function and then adds it to Boolean.prototype

function isFalse( ){
     if (this.toString() == "false")
          return true;
     else
         return false;
 }
 Boolean.prototype.isFalse = isFalse;
 var bool = new Boolean(1);
 document.write(bool.isFalse());

 // Output:
 // false

Adds a function directly to the Boolean object through its prototype

//Creates a toggle function for Boolean objects
// through its prototype. All new boolean objects will
// have this method.
Boolean.prototype.toggle = function (){
  return !this.valueOf();
}

Remarks

The boolean argument is the name of an object.

The prototype property provides a base set of functionality to a class of objects. New instances of an object “inherit” the behavior of the prototype assigned to that object. Properties and methods may be added to the prototype, but builtin objects may not be assigned a different prototype.

For example, to add a method to the Boolean object that returns the value of the largest element of the array, declare the function, add it to Boolean.prototype , and then use it.

Attributions

• Microsoft Developer Network: Article