高手提领 之 Douglas Crockford: "Advanced JavaScript"
视频地址：http://video.yahoo.com/watch/111585/1027823
PPT下载：http://yuiblog.com/assets/crockford/advancedjavascript.zip
关于闭包（Closure）
Flexible, but Why we do that?
////////////////////////////////////////
Regular Singleton :
var singleton = {
firstMethod: function (a, b) {
...
},
secondMethod: function (c) {
...
}
};
////////////////////////////////////////
For Private Variables:
var singleton = function () {
var privateVariable;
function privateFunction(x) {
...privateVariable...
}
return {
firstMethod: function (a, b) {
...privateVariable...
},
secondMethod: function (c) {
...privateFunction()...
}
};
}();
////////////////////////////////////////
Return Private Object:
function powerConstructor() {
var that = object(oldObject),
privateVariable;
function privateFunction(x) {}
that.firstMethod = function (a, b) {
...privateVariable...
};
that.secondMethod = function (c) {
...privateFunction()...
};
return that;
}
////////////////////////////////////////
Regular Inheritance:
function Gizmo(id) {
this.id = id;
}
Gizmo.prototype.toString = function () {
return "gizmo " + this.id;
};
function Hoozit(id) {
this.id = id;
}
Hoozit.prototype = new Gizmo();
Hoozit.prototype.test = function (id) {
return this.id === id;
};
////////////////////////////////////////
Inheritance save code:
function gizmo(id) {
return {
id: id,
toString: function () {
return "gizmo " + this.id;
}
};
}
function hoozit(id) {
var that = gizmo(id);
that.test = function (testid) {
return testid === this.id;
};
return that;
}
////////////////////////////////////////
Private Property:
function gizmo(id) {
return {
toString: function () {
return "gizmo " + id;
}
};
}
function hoozit(id) {
var that = gizmo(id);
that.test = function (testid) {
return testid === id;
};
return that;
}
////////////////////////////////////////
Protected Property:
function gizmo(id, secret) {
secret = secret || {};
secret.id = id;
return {
toString: function () {
return "gizmo " + secret.id;
};
};
}
function hoozit(id) {
var secret = {}, /*final*/
that = gizmo(id, secret);
that.test = function (testid) {
return testid === secret.id;
};
return that;
}
////////////////////////////////////////
Call Super Function:
function hoozit(id) {
var secret = {},
that = gizmo(id, secret),
super_toString = that.toString;
that.test = function (testid) {
return testid === secret.id;
};
that.toString = function () {
return super_toString.apply(that, []);
};
return that;
}