Modify javascript objects

In javascript, we can use the prototype attribute to create a new method for an existing class.
For example, the Number class is an original class provided by javascript. Now we add a toHexString method to it. This method is used to return the hexadecimal result of an integer. Number. prototype. toHexString = function ()
{
Return this. toString (16 );
}

Var I = 15;
Alert (I. toHexString (); // The result is f.

In this way, we can add the new method we need for an existing class.
You can also use the prototype attribute to redefine existing classes.
For example, if the toString method of the original Function is to return the original code of the Function, we can redefine the output of other text Function. prototype. toString = function ()
{
Alert ("this is a function ");
}

Function hello ()
{
Alert ("hello ");
}

Alert (hello. toString (); // display as this is a function