如何在Javascript中访问其他对象的私有方法（但它是同一个instanceof）

Question

var a1 = new A("test")
var a2 = new A("test2")
console.log(a2.getOtherValue(a1)) // -> expected "test"
a2.setOtherValue(a1, "test3") // set another object value
console.log(a1.getValue()) // -> expected "test3"

How Can I implement this??

Answer 1

You can use getter and setter methods to create a property and on add, you can mutate own value. Mutating other object using current object is a bad idea.

Following is a sample:

 function MyNumber(value) { var _value = value; Object.defineProperty(this, 'value', { get: function() { return _value; }, set: function(v) { if(!isNaN(v)) _value = v; } }); } MyNumber.prototype = (function() { var proto = {}; proto.add = function(o2) { if (o2 instanceof MyNumber) { this.value = this.value + o2.value; } else { throw new Error('Mismatched type. Expected an object of type MyNumber but got ' + o2.constructor.name); } } return proto; })(); var o1 = new MyNumber(10); var o2 = new MyNumber(20); o1.add(o2); console.log(o1.value); var o3 = { value: 40 } try { o1.add(o3); } catch (ex) { console.log(ex.message) }