简单的javascript继承:
/* Simple JavaScript Inheritance
* By John Resig http://ejohn.org/
* MIT Licensed.
*/
// Inspired by base2 and Prototype
(function(){
var initializing = false,
fnTest = /xyz/.test(function(){xyz;}) ? /\b_super\b/ : /.*/;
// The base Class implementation (does nothing)
this.Class = function(){};
// Create a new Class that inherits from this class
Class.extend = function(prop) {
var _super = this.prototype;
// Instantiate a base class (but only create the instance,
// don't run the init constructor)
initializing = true;
var prototype = new this();
initializing = false;
// Copy the properties over onto the new prototype
for (var name in prop) {
// Check if we're overwriting an existing function
prototype[name] = typeof prop[name] == "function" &&
typeof _super[name] == "function" && fnTest.test(prop[name]) ?
(function(name, fn){
return function() {
var tmp = this._super;
// Add a new ._super() method that is the same method
// but on the super-class
this._super = _super[name];
// The method only need to be bound temporarily, so we
// remove it when we're done executing
var ret = fn.apply(this, arguments);
this._super = tmp;
return ret;
};
})(name, prop[name]) :
prop[name];
}
// The dummy class constructor
function Class() {
// All construction is actually done in the init method
if ( !initializing && this.init )
this.init.apply(this, arguments);
}
// Populate our constructed prototype object
Class.prototype = prototype;
// Enforce the constructor to be what we expect
Class.prototype.constructor = Class;
// And make this class extendable
Class.extend = arguments.callee;
return Class;
};
})();
使用继承:
var Person = Class.extend({
init: function(isDancing){
this.dancing = isDancing;
},
dance: function(){
return this.dancing;
}
});
var Ninja = Person.extend({
init: function(){
this._super( false );
},
dance: function(){
// Call the inherited version of dance()
return this._super();
},
swingSword: function(){
return true;
}
});
在html页面里的使用方法:
<html> <head> <script src="./jquery-latest.js"></script> <script src="./simple_init.js"></script> <script src="./my_extend.js"></script> </head> <body> <div id="test" height="100px" width="100px"></div> </body> <footer> </footer> </html> <script> var n = new Ninja(); // console.log(n.dance()); // => false // n.swingSword(); // => true </script>