javascript 类，只读属性，闭包

function employee(_name, _dept){    this.getName = (function(){ return _name; })();    this.getDept = (function(){ return _dept; })();}employee.prototype={ say:'hello' }//父类赋值var x = new employee('test1',2);//x继承console.log(x.say);x.__proto__={say:'hi'};//x改自己的console.log(x.say);var y = new employee('test2', 1);//y继承console.log(y.say);y.__proto__.say = 'are you ok?';//y改父类的 console.log(y.say);var z = new employee('test3');//z继承console.log(z.say);

运行结果

hello
hi
hello
are you ok?
are you ok?