Developer Snippets - An Embodiment for Developers

John Resig, has explained us a better and interesting way of Method Overloading. Here he has discussed about the ability to run different code depending on the number of arguments passed into the same function. For those who are not familiar with, it’s just a way of mapping a single function call to multiple functions based on arguments they accept.

Function:

// addMethod - By John Resig (MIT Licensed)
function addMethod(object, name, fn){
    var old = object[ name ];
    object[ name ] = function(){
        if ( fn.length == arguments.length )
            return fn.apply( this, arguments );
        else if ( typeof old == 'function' )
            return old.apply( this, arguments );
    };
}

Using It:

function Users(){
   addMethod(this, "find", function(){
     // Find all users...
   });
   addMethod(this, "find", function(name){
     // Find a user by name
   });
   addMethod(this, "find", function(first, last){
     // Find a user by first and last name
   });
 }

Using object prototype:

 function Users(){}
 addMethod(Users.prototype, "find", function(){
   // Find all users...
 });
 addMethod(Users.prototype, "find", function(name){
   // Find a user by name
 });
 addMethod(Users.prototype, "find", function(first, last){
   // Find a user by first and last name
 });

End Result:

var users = new Users();
users.find(); // Finds all
users.find("John"); // Finds users by name
users.find("John", "Resig"); // Finds users by first and last name
users.find("John", "E", "Resig"); // Does nothing

Hope the above will help developers a lot!

Rock Up the Web World!!!