javascript - 有人可以解释这个 OOP javascript 结构吗

Question

谁能解释一下这个 OOP javascript 结构？

我知道这是在 javascript 中创建“对象”的方式，只需要对符号及其含义做一些解释:

 var vote = function(){
     return {
            P1: function() {
                alert('P1');
            },

            P2: function() {
                alert('P2');
            }          

        };

    }();

    vote.P1();
    vote.P2();

1. 为什么返回调用中有公共(public)方法？这怎么可能？用逗号分隔？

2. 为什么'object'的结尾必须是(); ?

3. 内部方法和公共(public)方法的命名约定？

4. 公共(public)属性和方法是否具有相同的结构？有什么区别？

Answer 1

var vote = function(){
    var privateMember = 3; // lets define a private member, this will only be available inside the function scope, so we can't do "vote.privateMember" because we're not returning it below

    // It's returning an object, {}
    // these are considered public because they are returned by the function, making them available outside the function scope using the "dot" operator, "vote.P1()"
    return {
        // first value of the object is a function
        // so we can call this like "vote.P1()"
        // we're calling a privateMember in here
        P1: function() {
            alert('P1');
            alert(privateMember);
        },
        // second value of the object is a function
        // so we can call this like "vote.P2()"
        P2: function() {
            alert('P2');
        }          
    };
}(); // () means it will execute the function, so "vote" will store the return value of this function, it's a shorthand for `var vote = function(){}; vote = vote();

私有(private)方法的命名约定通常是在方法/属性名称前加上下划线 _privateMethod: function(){}。