Method overload instance _javascript techniques in JavaScript

. NET inside the method overload is indeed very convenient, which JavaScript can also do what?

Javasciprt There is no way to overload the function, many people before the practice may be directly less pass parameters, and then in accordance with the parameters are not defined as "undefined" to determine how to deal with, so as to achieve a similar method overload functionality.

For example:

Copy Code code as follows:

var showmessage = function (name,value,id) {
if (id!= "undefined") {
alert (Name+value+id);
}
else if (value!= "undefined") {
Alert (name + value);
}
else{
alert (name);
}
}

ShowMessage ("haha");
ShowMessage ("haha", "??") ”);
ShowMessage ("haha", "??") ", 124124);

Today, on Ajaxian, I saw an article on the JavaScript method overload, which can be done in another way.

Take a look at this code:

Copy Code code as follows:

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);
}
}
};

var UserInfo = function () {
Addmethod (this, ' Find ', function () {
Alert ("No parameters");
});

Addmethod (this, ' Find ', function (name) {
Alert ("Incoming parameter is one, called" +name);
});

Addmethod (this, ' Find ', function (name,value) {
Alert ("passed in two parameters, one is called name=" +name+ "one is called value=" +value);
});
};

var userinfo = new UserInfo ();
Userinfo.find ();
Userinfo.find (' Who am I? ');
Userinfo.find (' So-and-so ', ' 1512412514 ');

Look, this is simple ...