要创建一个带有公共方法的JavaScript类，我可以这样做:
function Restaurant() {}
Restaurant.prototype.buy_food = function(){
// something here
}
Restaurant.prototype.use_restroom = function(){
// something here
}
这样，我类的用户就可以:
var restaurant = new Restaurant();
restaurant.buy_food();
restaurant.use_restroom();
如何创建一个私有方法，可以由buy_food和use_restroom方法调用，但不能由类的用户外部调用?
换句话说，我希望我的方法实现能够做到:
Restaurant.prototype.use_restroom = function() {
this.private_stuff();
}
但这是行不通的:
var r = new Restaurant();
r.private_stuff();
如何将private_stuff定义为私有方法，使两者都成立?
我读过Doug Crockford的文章几次，但它似乎不像“私有”方法可以被公共方法调用，而“特权”方法可以被外部调用。
var TestClass = function( ) {
var privateProperty = 42;
function privateMethod( ) {
alert( "privateMethod, " + privateProperty );
}
this.public = {
constructor: TestClass,
publicProperty: 88,
publicMethod: function( ) {
alert( "publicMethod" );
privateMethod( );
}
};
};
TestClass.prototype = new TestClass( ).public;
var myTestClass = new TestClass( );
alert( myTestClass.publicProperty );
myTestClass.publicMethod( );
alert( myTestClass.privateMethod || "no privateMethod" );
类似于georgebrock，但不太啰嗦(恕我直言)
这样做有什么问题吗?(我哪儿都没见过)
编辑:我意识到这有点没用，因为每个独立的实例化都有自己的公共方法副本，从而破坏了原型的使用。
一个丑陋但有效的解决方案:
function Class(cb) {
const self = {};
const constructor = (fn) => {
func = fn;
};
const addPrivate = (fnName, obj) => {
self[fnName] = obj;
}
const addPublic = (fnName, obj) => {
this[fnName] = obj;
self[fnName] = obj;
func.prototype[fnName] = obj;
}
cb(constructor, addPrivate, addPublic, self);
return func;
}
const test = new Class((constructor, private, public, self) => {
constructor(function (test) {
console.log(test)
});
public('test', 'yay');
private('qwe', 'nay');
private('no', () => {
return 'hello'
})
public('asd', () => {
return 'this is public'
})
public('hello', () => {
return self.qwe + self.no() + self.asd()
})
})
const asd = new test('qweqwe');
console.log(asd.hello());
这是我得出的结论:
需要一类糖代码，你可以在这里找到。还支持保护，继承，虚拟，静态的东西…
;( function class_Restaurant( namespace )
{
'use strict';
if( namespace[ "Restaurant" ] ) return // protect against double inclusions
namespace.Restaurant = Restaurant
var Static = TidBits.OoJs.setupClass( namespace, "Restaurant" )
// constructor
//
function Restaurant()
{
this.toilets = 3
this.Private( private_stuff )
return this.Public( buy_food, use_restroom )
}
function private_stuff(){ console.log( "There are", this.toilets, "toilets available") }
function buy_food (){ return "food" }
function use_restroom (){ this.private_stuff() }
})( window )
var chinese = new Restaurant
console.log( chinese.buy_food() ); // output: food
console.log( chinese.use_restroom() ); // output: There are 3 toilets available
console.log( chinese.toilets ); // output: undefined
console.log( chinese.private_stuff() ); // output: undefined
// and throws: TypeError: Object #<Restaurant> has no method 'private_stuff'
