上一篇寫了個工具函數$class，這篇再完善以下。實現以下功能
1，繼承
2，子類繼承父類時，不繼承父類的私有屬性
/**
* @param {String} className
* @param {String/Function} superCls
* @param {Function} classImp
*/
function $class(className, superCls, classImp){
if(superCls === '') superCls = Object;
function clazz(){
if(typeof this.init == "function"){
this.init.apply(this, arguments);
}
}
var p = clazz.prototype = new superCls();
var _super = superCls.prototype;
window[className] = clazz;
classImp.apply(p, [_super]);
}
先寫個父類
/**
* 父類 Person
*/
$class('Person','',function(){
// 私有屬性age
var age;
this.init = function(n, a){
// 公有屬性name
this.name = n;
// 私有屬性初始化
age = a;
};
this.getName = function(){
return this.name;
};
this.setName = function(name){
this.name = name;
}
this.getAge = function(){
return age;
};
this.setAge = function(a){
age = a;
};
});
寫子類，繼承于Person
$class("Man",Person, function(supr){
var school;
this.init = function(n, a, s){
supr.init.apply(this, [n,a]);
school = s;
}
this.getSchool = function(){
return school;
};
this.setSchool = function(s){
school = s;
};
});
new一個子類實例
var m = new Man('tom', 25, 'pku');
console.log(m.name); // tom 繼承父類的共有屬性name可以直接使用點操作符獲取
console.log(m.age); // undefined 父類的私有屬性age不能直接使用點操作符獲取
console.log(m.getAge()); // 25 可通過父類的共有方法getAge獲取私有屬性age
console.log(m.school); // undefined Man自己的私有屬性仍然不能通過點操作符獲取
console.log(m.getSchool()); // pku 通過getSchool()方法獲取私有屬性school
